gis: Refactor of the `GeoQuerySet`; new features include:

 (1) Creation of internal API that eases generation of `GeoQuerySet` methods.
 (2) `GeoQuerySet.distance` now returns `Distance` objects instead of floats.
 (3) Added the new `GeoQuerySet` methods: `area`, `centroid`, `difference`, `envelope`, `intersection`, `length`, `make_line`, `mem_size`, `num_geom`, `num_points`, `perimeter`, `point_on_surface`, `scale`, `svg`, `sym_difference`, `translate`, `union`.
 (4) The `model_att` keyword may be used to customize the attribute that `GeoQuerySet` methods attach output to.
 (5) Geographic distance lookups and `GeoQuerySet.distance` calls now use `ST_distance_sphere` by default (performance benefits far outweigh small loss in accuracy); `ST_distance_spheroid` may still be used by specifying an option.
 (6) `GeoQuerySet` methods may now operate accross ForeignKey relations specified via the `field_name` keyword (but this does not work on Oracle).
 (7) `Area` now has the same units of measure as `Distance`.

Backward Incompatibilites:
 * The aggregate union method is now known as `unionagg`.
 * The `field_name` keyword used for `GeoQuerySet` methods may no longer be specified via positional arguments.
 * `Distance` objects returned instead of floats from `GeoQuerySet.distance`.
 * `ST_Distance_sphere` used by default for geographic distance calculations.


git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@7641 bcc190cf-cafb-0310-a4f2-bffc1f526a37

27 files changed, 1362 insertions, 539 deletions

diff --git a/django/contrib/gis/db/backend/__init__.py b/django/contrib/gis/db/backend/__init__.py
index cb027b9eec..172c1268a7 100644
--- a/django/contrib/gis/db/backend/__init__.py
+++ b/django/contrib/gis/db/backend/__init__.py
@@ -3,97 +3,16 @@
 
  Specifically, this module will import the correct routines and modules
  needed for GeoDjango to interface with the spatial database.
- 
- Some of the more important classes and routines from the spatial backend
- include:
-
- (1) `GeoBackEndField`, a base class needed for GeometryField.
- (2) `get_geo_where_clause`, a routine used by `GeoWhereNode`.
- (3) `GIS_TERMS`, a listing of all valid GeoDjango lookup types.
- (4) `SpatialBackend`, a container object for information specific to the
-     spatial backend.
 """
 from django.conf import settings
-from django.db.models.sql.query import QUERY_TERMS
 from django.contrib.gis.db.backend.util import gqn
 
-# These routines (needed by GeoManager), default to False.
-ASGML, ASKML, DISTANCE, DISTANCE_SPHEROID, EXTENT, TRANSFORM, UNION, VERSION = tuple(False for i in range(8))
-
-# Lookup types in which the rest of the parameters are not
-# needed to be substitute in the WHERE SQL (e.g., the 'relate'
-# operation on Oracle does not need the mask substituted back
-# into the query SQL.).
-LIMITED_WHERE = []
-
 # Retrieving the necessary settings from the backend.
 if settings.DATABASE_ENGINE == 'postgresql_psycopg2':
-    from django.contrib.gis.db.backend.postgis.adaptor import \
-        PostGISAdaptor as GeoAdaptor
-    from django.contrib.gis.db.backend.postgis.field import \
-        PostGISField as GeoBackendField
-    from django.contrib.gis.db.backend.postgis.creation import create_spatial_db
-    from django.contrib.gis.db.backend.postgis.query import \
-        get_geo_where_clause, POSTGIS_TERMS as GIS_TERMS, \
-        ASGML, ASKML, DISTANCE, DISTANCE_SPHEROID, DISTANCE_FUNCTIONS, \
-        EXTENT, GEOM_SELECT, TRANSFORM, UNION, \
-        MAJOR_VERSION, MINOR_VERSION1, MINOR_VERSION2
-    # PostGIS version info is needed to determine calling order of some
-    # stored procedures (e.g., AsGML()).
-    VERSION = (MAJOR_VERSION, MINOR_VERSION1, MINOR_VERSION2)
-    SPATIAL_BACKEND = 'postgis'
+    from django.contrib.gis.db.backend.postgis import create_spatial_db, get_geo_where_clause, SpatialBackend
 elif settings.DATABASE_ENGINE == 'oracle':
-    from django.contrib.gis.db.backend.adaptor import WKTAdaptor as GeoAdaptor
-    from django.contrib.gis.db.backend.oracle.field import \
-        OracleSpatialField as GeoBackendField
-    from django.contrib.gis.db.backend.oracle.creation import create_spatial_db
-    from django.contrib.gis.db.backend.oracle.query import \
-        get_geo_where_clause, ORACLE_SPATIAL_TERMS as GIS_TERMS, \
-        ASGML, DISTANCE, DISTANCE_FUNCTIONS, GEOM_SELECT, TRANSFORM, UNION
-    SPATIAL_BACKEND = 'oracle'
-    LIMITED_WHERE = ['relate']
+    from django.contrib.gis.db.backend.oracle import create_spatial_db, get_geo_where_clause, SpatialBackend
 elif settings.DATABASE_ENGINE == 'mysql':
-    from django.contrib.gis.db.backend.adaptor import WKTAdaptor as GeoAdaptor
-    from django.contrib.gis.db.backend.mysql.field import \
-        MySQLGeoField as GeoBackendField
-    from django.contrib.gis.db.backend.mysql.creation import create_spatial_db
-    from django.contrib.gis.db.backend.mysql.query import \
-        get_geo_where_clause, MYSQL_GIS_TERMS as GIS_TERMS, GEOM_SELECT
-    DISTANCE_FUNCTIONS = {}
-    SPATIAL_BACKEND = 'mysql'
+    from django.contrib.gis.db.backend.mysql import create_spatial_db, get_geo_where_clause, SpatialBackend
 else:
     raise NotImplementedError('No Geographic Backend exists for %s' % settings.DATABASE_ENGINE)
-
-class SpatialBackend(object):
-    "A container for properties of the SpatialBackend."
-    # Stored procedure names used by the `GeoManager`.
-    as_kml = ASKML
-    as_gml = ASGML
-    distance = DISTANCE
-    distance_spheroid = DISTANCE_SPHEROID
-    extent = EXTENT
-    name = SPATIAL_BACKEND
-    select = GEOM_SELECT
-    transform = TRANSFORM
-    union = UNION
-    
-    # Version information, if defined.
-    version = VERSION
-    
-    # All valid GIS lookup terms, and distance functions.
-    gis_terms = GIS_TERMS
-    distance_functions = DISTANCE_FUNCTIONS
-    
-    # Lookup types where additional WHERE parameters are excluded.
-    limited_where = LIMITED_WHERE
-
-    # Shortcut booleans.
-    mysql = SPATIAL_BACKEND == 'mysql'
-    oracle = SPATIAL_BACKEND == 'oracle'
-    postgis = SPATIAL_BACKEND == 'postgis'
-
-    # Class for the backend field.
-    Field = GeoBackendField
-
-    # Adaptor class used for quoting GEOS geometries in the database.
-    Adaptor = GeoAdaptor
diff --git a/django/contrib/gis/db/backend/base.py b/django/contrib/gis/db/backend/base.py
new file mode 100644
index 0000000000..d45ac7b6f1
--- /dev/null
+++ b/django/contrib/gis/db/backend/base.py
@@ -0,0 +1,29 @@
+"""
+ This module holds the base `SpatialBackend` object, which is
+ instantiated by each spatial backend with the features it has.
+"""
+# TODO: Create a `Geometry` protocol and allow user to use
+# different Geometry objects -- for now we just use GEOSGeometry.
+from django.contrib.gis.geos import GEOSGeometry, GEOSException
+
+class BaseSpatialBackend(object):
+    Geometry = GEOSGeometry
+    GeometryException = GEOSException
+
+    def __init__(self, **kwargs):
+        kwargs.setdefault('distance_functions', {})
+        kwargs.setdefault('limited_where', {})
+        for k, v in kwargs.iteritems(): setattr(self, k, v)
+ 
+    def __getattr__(self, name):
+        """
+        All attributes of the spatial backend return False by default.
+        """
+        try:
+            return self.__dict__[name]
+        except KeyError:
+            return False
+            
+        
+        
+    
diff --git a/django/contrib/gis/db/backend/mysql/__init__.py b/django/contrib/gis/db/backend/mysql/__init__.py
index 8b13789179..0484e5f9b2 100644
--- a/django/contrib/gis/db/backend/mysql/__init__.py
+++ b/django/contrib/gis/db/backend/mysql/__init__.py
@@ -1 +1,13 @@
+__all__ = ['create_spatial_db', 'get_geo_where_clause', 'SpatialBackend']
 
+from django.contrib.gis.db.backend.base import BaseSpatialBackend
+from django.contrib.gis.db.backend.adaptor import WKTAdaptor
+from django.contrib.gis.db.backend.mysql.creation import create_spatial_db
+from django.contrib.gis.db.backend.mysql.field import MySQLGeoField
+from django.contrib.gis.db.backend.mysql.query import *
+
+SpatialBackend = BaseSpatialBackend(name='mysql', mysql=True,
+                                    gis_terms=MYSQL_GIS_TERMS,
+                                    select=GEOM_SELECT,
+                                    Adaptor=WKTAdaptor,
+                                    Field=MySQLGeoField)
diff --git a/django/contrib/gis/db/backend/oracle/__init__.py b/django/contrib/gis/db/backend/oracle/__init__.py
index e69de29bb2..3eee56ea23 100644
--- a/django/contrib/gis/db/backend/oracle/__init__.py
+++ b/django/contrib/gis/db/backend/oracle/__init__.py
@@ -0,0 +1,31 @@
+__all__ = ['create_spatial_db', 'get_geo_where_clause', 'SpatialBackend']
+
+from django.contrib.gis.db.backend.base import BaseSpatialBackend
+from django.contrib.gis.db.backend.oracle.adaptor import OracleSpatialAdaptor
+from django.contrib.gis.db.backend.oracle.creation import create_spatial_db
+from django.contrib.gis.db.backend.oracle.field import OracleSpatialField
+from django.contrib.gis.db.backend.oracle.query import *
+
+SpatialBackend = BaseSpatialBackend(name='oracle', oracle=True,
+                                    area=AREA,
+                                    centroid=CENTROID,
+                                    difference=DIFFERENCE,
+                                    distance=DISTANCE,
+                                    distance_functions=DISTANCE_FUNCTIONS,
+                                    gis_terms=ORACLE_SPATIAL_TERMS,
+                                    gml=ASGML,
+                                    intersection=INTERSECTION,
+                                    length=LENGTH,
+                                    limited_where = {'relate' : None},
+                                    num_geom=NUM_GEOM,
+                                    num_points=NUM_POINTS,
+                                    perimeter=LENGTH,
+                                    point_on_surface=POINT_ON_SURFACE,
+                                    select=GEOM_SELECT,
+                                    sym_difference=SYM_DIFFERENCE,
+                                    transform=TRANSFORM,
+                                    unionagg=UNIONAGG,
+                                    union=UNION,
+                                    Adaptor=OracleSpatialAdaptor,
+                                    Field=OracleSpatialField,
+                                    )
diff --git a/django/contrib/gis/db/backend/oracle/adaptor.py b/django/contrib/gis/db/backend/oracle/adaptor.py
new file mode 100644
index 0000000000..95dc265795
--- /dev/null
+++ b/django/contrib/gis/db/backend/oracle/adaptor.py
@@ -0,0 +1,5 @@
+from cx_Oracle import CLOB
+from django.contrib.gis.db.backend.adaptor import WKTAdaptor
+
+class OracleSpatialAdaptor(WKTAdaptor):
+    input_size = CLOB
diff --git a/django/contrib/gis/db/backend/oracle/query.py b/django/contrib/gis/db/backend/oracle/query.py
index d4cd3669e2..6f5c0dfe94 100644
--- a/django/contrib/gis/db/backend/oracle/query.py
+++ b/django/contrib/gis/db/backend/oracle/query.py
@@ -15,10 +15,21 @@ from django.contrib.gis.measure import Distance
 qn = connection.ops.quote_name

 

 # The GML, distance, transform, and union procedures.

+AREA = 'SDO_GEOM.SDO_AREA'

 ASGML = 'SDO_UTIL.TO_GMLGEOMETRY'

+CENTROID = 'SDO_GEOM.SDO_CENTROID'

+DIFFERENCE = 'SDO_GEOM.SDO_DIFFERENCE'

 DISTANCE = 'SDO_GEOM.SDO_DISTANCE'

+EXTENT = 'SDO_AGGR_MBR'

+INTERSECTION = 'SDO_GEOM.SDO_INTERSECTION'

+LENGTH = 'SDO_GEOM.SDO_LENGTH'

+NUM_GEOM = 'SDO_UTIL.GETNUMELEM'

+NUM_POINTS = 'SDO_UTIL.GETNUMVERTICES'

+POINT_ON_SURFACE = 'SDO_GEOM.SDO_POINTONSURFACE'

+SYM_DIFFERENCE = 'SDO_GEOM.SDO_XOR'

 TRANSFORM = 'SDO_CS.TRANSFORM'

-UNION = 'SDO_AGGR_UNION'

+UNION = 'SDO_GEOM.SDO_UNION'

+UNIONAGG = 'SDO_AGGR_UNION'

 

 # We want to get SDO Geometries as WKT because it is much easier to 

 # instantiate GEOS proxies from WKT than SDO_GEOMETRY(...) strings.  

diff --git a/django/contrib/gis/db/backend/postgis/__init__.py b/django/contrib/gis/db/backend/postgis/__init__.py
index e69de29bb2..8a4d09e0d5 100644
--- a/django/contrib/gis/db/backend/postgis/__init__.py
+++ b/django/contrib/gis/db/backend/postgis/__init__.py
@@ -0,0 +1,42 @@
+__all__ = ['create_spatial_db', 'get_geo_where_clause', 'SpatialBackend']
+
+from django.contrib.gis.db.backend.base import BaseSpatialBackend
+from django.contrib.gis.db.backend.postgis.adaptor import PostGISAdaptor
+from django.contrib.gis.db.backend.postgis.creation import create_spatial_db
+from django.contrib.gis.db.backend.postgis.field import PostGISField
+from django.contrib.gis.db.backend.postgis.query import *
+
+SpatialBackend = BaseSpatialBackend(name='postgis', postgis=True,
+                                    area=AREA,
+                                    centroid=CENTROID,
+                                    difference=DIFFERENCE,
+                                    distance=DISTANCE,
+                                    distance_functions=DISTANCE_FUNCTIONS,
+                                    distance_sphere=DISTANCE_SPHERE,
+                                    distance_spheroid=DISTANCE_SPHEROID,
+                                    envelope=ENVELOPE,
+                                    extent=EXTENT,
+                                    gis_terms=POSTGIS_TERMS,
+                                    gml=ASGML,
+                                    intersection=INTERSECTION,
+                                    kml=ASKML,
+                                    length=LENGTH,
+                                    length_spheroid=LENGTH_SPHEROID,
+                                    make_line=MAKE_LINE,
+                                    mem_size=MEM_SIZE,
+                                    num_geom=NUM_GEOM,
+                                    num_points=NUM_POINTS,
+                                    perimeter=PERIMETER,
+                                    point_on_surface=POINT_ON_SURFACE,
+                                    scale=SCALE,
+                                    select=GEOM_SELECT,
+                                    svg=ASSVG,
+                                    sym_difference=SYM_DIFFERENCE,
+                                    transform=TRANSFORM,
+                                    translate=TRANSLATE,
+                                    union=UNION,
+                                    unionagg=UNIONAGG,
+                                    version=(MAJOR_VERSION, MINOR_VERSION1, MINOR_VERSION2),
+                                    Adaptor=PostGISAdaptor,
+                                    Field=PostGISField,
+                                    )
diff --git a/django/contrib/gis/db/backend/postgis/field.py b/django/contrib/gis/db/backend/postgis/field.py
index 9e20a72eee..1e055ff60b 100644
--- a/django/contrib/gis/db/backend/postgis/field.py
+++ b/django/contrib/gis/db/backend/postgis/field.py
@@ -1,6 +1,5 @@
 from django.db import connection
 from django.db.models.fields import Field # Django base Field class
-from django.contrib.gis.geos import GEOSGeometry
 from django.contrib.gis.db.backend.util import gqn
 from django.contrib.gis.db.backend.postgis.query import TRANSFORM
 
diff --git a/django/contrib/gis/db/backend/postgis/query.py b/django/contrib/gis/db/backend/postgis/query.py
index 2610173673..90063e1887 100644
--- a/django/contrib/gis/db/backend/postgis/query.py
+++ b/django/contrib/gis/db/backend/postgis/query.py
@@ -21,7 +21,7 @@ if MAJOR_VERSION != 1 or (MAJOR_VERSION == 1 and MINOR_VERSION1 < 1):
 
 # Versions of PostGIS >= 1.2.2 changed their naming convention to be
 #  'SQL-MM-centric' to conform with the ISO standard. Practically, this
-#  means that 'ST_' is prefixes geometry function names.
+#  means that 'ST_' prefixes geometry function names.
 GEOM_FUNC_PREFIX = ''
 if MAJOR_VERSION >= 1:
     if (MINOR_VERSION1 > 2 or
@@ -30,26 +30,46 @@ if MAJOR_VERSION >= 1:
 
     def get_func(func): return '%s%s' % (GEOM_FUNC_PREFIX, func)
 
-    # Custom selection not needed for PostGIS since GEOS geometries may be
+    # Custom selection not needed for PostGIS because GEOS geometries are
     # instantiated directly from the HEXEWKB returned by default.  If
     # WKT is needed for some reason in the future, this value may be changed,
-    # 'AsText(%s)'
+    # e.g,, 'AsText(%s)'.
     GEOM_SELECT = None
 
     # Functions used by the GeoManager & GeoQuerySet
+    AREA = get_func('Area')
     ASKML = get_func('AsKML')
     ASGML = get_func('AsGML')
+    ASSVG = get_func('AsSVG')
+    CENTROID = get_func('Centroid')
+    DIFFERENCE = get_func('Difference')
     DISTANCE = get_func('Distance')
+    DISTANCE_SPHERE = get_func('distance_sphere')
     DISTANCE_SPHEROID = get_func('distance_spheroid')
+    ENVELOPE = get_func('Envelope')
     EXTENT = get_func('extent')
     GEOM_FROM_TEXT = get_func('GeomFromText')
     GEOM_FROM_WKB = get_func('GeomFromWKB')
+    INTERSECTION = get_func('Intersection')
+    LENGTH = get_func('Length')
+    LENGTH_SPHEROID = get_func('length_spheroid')
+    MAKE_LINE = get_func('MakeLine')
+    MEM_SIZE = get_func('mem_size')
+    NUM_GEOM = get_func('NumGeometries')
+    NUM_POINTS = get_func('npoints')
+    PERIMETER = get_func('Perimeter')
+    POINT_ON_SURFACE = get_func('PointOnSurface')
+    SCALE = get_func('Scale')
+    SYM_DIFFERENCE = get_func('SymDifference')
     TRANSFORM = get_func('Transform')
+    TRANSLATE = get_func('Translate')
 
     # Special cases for union and KML methods.
     if MINOR_VERSION1 < 3:
-        UNION = 'GeomUnion'
+        UNIONAGG = 'GeomUnion'
+        UNION = 'Union'
     else:
+        UNIONAGG = 'ST_Union'
         UNION = 'ST_Union'
 
     if MINOR_VERSION1 == 1:
@@ -80,16 +100,23 @@ class PostGISDistance(PostGISFunction):
         super(PostGISDistance, self).__init__(self.dist_func, end_subst=') %s %s', 
                                               operator=operator, result='%%s')
 
-class PostGISSphereDistance(PostGISFunction):
-    "For PostGIS spherical distance operations."
+class PostGISSpheroidDistance(PostGISFunction):
+    "For PostGIS spherical distance operations (using the spheroid)."
     dist_func = 'distance_spheroid'
     def __init__(self, operator):
         # An extra parameter in `end_subst` is needed for the spheroid string.
-        super(PostGISSphereDistance, self).__init__(self.dist_func, 
-                                                    beg_subst='%s(%s, %%s, %%s', 
-                                                    end_subst=') %s %s',
-                                                    operator=operator, result='%%s')
+        super(PostGISSpheroidDistance, self).__init__(self.dist_func, 
+                                                      beg_subst='%s(%s, %%s, %%s', 
+                                                      end_subst=') %s %s',
+                                                      operator=operator, result='%%s')
 
+class PostGISSphereDistance(PostGISFunction):
+    "For PostGIS spherical distance operations."
+    dist_func = 'distance_sphere'
+    def __init__(self, operator):
+        super(PostGISSphereDistance, self).__init__(self.dist_func, end_subst=') %s %s',
+                                                    operator=operator, result='%%s')
+                                                    
 class PostGISRelate(PostGISFunctionParam):
     "For PostGIS Relate(<geom>, <pattern>) calls."
     pattern_regex = re.compile(r'^[012TF\*]{9}$')
@@ -164,7 +191,7 @@ POSTGIS_GEOMETRY_FUNCTIONS = {
 dtypes = (Decimal, Distance, float, int, long)
 def get_dist_ops(operator):
     "Returns operations for both regular and spherical distances."
-    return (PostGISDistance(operator), PostGISSphereDistance(operator))
+    return (PostGISDistance(operator), PostGISSphereDistance(operator), PostGISSpheroidDistance(operator))
 DISTANCE_FUNCTIONS = {
     'distance_gt' : (get_dist_ops('>'), dtypes),
     'distance_gte' : (get_dist_ops('>='), dtypes),
@@ -193,6 +220,13 @@ POSTGIS_TERMS += POSTGIS_GEOMETRY_FUNCTIONS.keys() # Adding on the Geometry Func
 POSTGIS_TERMS += MISC_TERMS # Adding any other miscellaneous terms (e.g., 'isnull')
 POSTGIS_TERMS = tuple(POSTGIS_TERMS) # Making immutable
 
+# For checking tuple parameters -- not very pretty but gets job done.
+def exactly_two(val): return val == 2
+def two_to_three(val): return val >= 2 and val <=3
+def num_params(lookup_type, val):
+    if lookup_type in DISTANCE_FUNCTIONS and lookup_type != 'dwithin': return two_to_three(val)
+    else: return exactly_two(val)
+
 #### The `get_geo_where_clause` function for PostGIS. ####
 def get_geo_where_clause(lookup_type, table_prefix, field, value):
     "Returns the SQL WHERE clause for use in PostGIS SQL construction."
@@ -216,8 +250,10 @@ def get_geo_where_clause(lookup_type, table_prefix, field, value):
             # Ensuring that a tuple _value_ was passed in from the user
             if not isinstance(value, (tuple, list)): 
                 raise TypeError('Tuple required for `%s` lookup type.' % lookup_type)
-            if len(value) != 2:
-                raise ValueError('2-element tuple required or `%s` lookup type.' % lookup_type)
+            # Number of valid tuple parameters depends on the lookup type.
+            nparams = len(value)
+            if not num_params(lookup_type, nparams):
+                raise ValueError('Incorrect number of parameters given for `%s` lookup type.' % lookup_type)
             
             # Ensuring the argument type matches what we expect.
             if not isinstance(value[1], arg_type):
@@ -234,7 +270,9 @@ def get_geo_where_clause(lookup_type, table_prefix, field, value):
                         raise TypeError('PostGIS spherical operations are only valid on PointFields.')
                     if value[0].geom_typeid != 0:
                         raise TypeError('PostGIS geometry distance parameter is required to be of type Point.')
-                    op = op[1]
+                    # Setting up the geodetic operation appropriately.
+                    if nparams == 3 and value[2] == 'spheroid': op = op[2]
+                    else: op = op[1]
                 else:
                     op = op[0]
         else:
diff --git a/django/contrib/gis/db/models/fields/__init__.py b/django/contrib/gis/db/models/fields/__init__.py
index f36045cf02..0a0d144dcc 100644
--- a/django/contrib/gis/db/models/fields/__init__.py
+++ b/django/contrib/gis/db/models/fields/__init__.py
@@ -3,15 +3,12 @@ from django.db import connection
 from django.contrib.gis.db.backend import SpatialBackend, gqn
 # GeometryProxy, GEOS, Distance, and oldforms imports.
 from django.contrib.gis.db.models.proxy import GeometryProxy
-from django.contrib.gis.geos import GEOSException, GEOSGeometry
 from django.contrib.gis.measure import Distance
 from django.contrib.gis.oldforms import WKTField
 
-# Attempting to get the spatial reference system.
-try:
-    from django.contrib.gis.models import SpatialRefSys
-except ImportError:
-    SpatialRefSys = None
+# The `get_srid_info` function gets SRID information from the spatial
+# reference system table w/o using the ORM.
+from django.contrib.gis.models import get_srid_info
 
 #TODO: Flesh out widgets; consider adding support for OGR Geometry proxies.
 class GeometryField(SpatialBackend.Field):
@@ -47,29 +44,7 @@ class GeometryField(SpatialBackend.Field):
         # Setting the SRID and getting the units.  Unit information must be 
         # easily available in the field instance for distance queries.
         self._srid = srid
-        if SpatialRefSys:
-            # Getting the spatial reference WKT associated with the SRID from the
-            # `spatial_ref_sys` (or equivalent) spatial database table.
-            #
-            # The following doesn't work: SpatialRefSys.objects.get(srid=srid)
-            # Why?  `syncdb` fails to recognize installed geographic models when there's
-            # an ORM query instantiated within a model field.
-            cur = connection.cursor()
-            qn = connection.ops.quote_name
-            stmt = 'SELECT %(table)s.%(wkt_col)s FROM %(table)s WHERE (%(table)s.%(srid_col)s = %(srid)s)'
-            stmt = stmt % {'table' : qn(SpatialRefSys._meta.db_table),
-                           'wkt_col' : qn(SpatialRefSys.wkt_col()),
-                           'srid_col' : qn('srid'),
-                           'srid' : srid,
-                           }
-            cur.execute(stmt)
-            srs_wkt = cur.fetchone()[0]
-            
-            # Getting metadata associated with the spatial reference system identifier.
-            # Specifically, getting the unit information and spheroid information 
-            # (both required for distance queries).
-            self._unit, self._unit_name = SpatialRefSys.get_units(srs_wkt)
-            self._spheroid = SpatialRefSys.get_spheroid(srs_wkt)
+        self._unit, self._unit_name, self._spheroid = get_srid_info(srid)
 
         # Setting the dimension of the geometry field.
         self._dim = dim
@@ -79,19 +54,26 @@ class GeometryField(SpatialBackend.Field):
     ### Routines specific to GeometryField ###
     @property
     def geodetic(self):
+        """
+        Returns true if this field's SRID corresponds with a coordinate
+        system that uses non-projected units (e.g., latitude/longitude).
+        """
         return self._unit_name in self.geodetic_units
 
-    def get_distance(self, dist, lookup_type):
+    def get_distance(self, dist_val, lookup_type):
         """
         Returns a distance number in units of the field.  For example, if 
         `D(km=1)` was passed in and the units of the field were in meters,
         then 1000 would be returned.
         """
-        postgis = SpatialBackend.name == 'postgis'
+        # Getting the distance parameter and any options.
+        if len(dist_val) == 1: dist, option = dist_val[0], None
+        else: dist, option = dist_val
+
         if isinstance(dist, Distance):
             if self.geodetic:
                 # Won't allow Distance objects w/DWithin lookups on PostGIS.
-                if postgis and lookup_type == 'dwithin':
+                if SpatialBackend.postgis and lookup_type == 'dwithin':
                     raise TypeError('Only numeric values of degree units are allowed on geographic DWithin queries.')
                 # Spherical distance calculation parameter should be in meters.
                 dist_param = dist.m
@@ -100,9 +82,11 @@ class GeometryField(SpatialBackend.Field):
         else:
             # Assuming the distance is in the units of the field.
             dist_param = dist
-
-        # Sphereical distance query; returning meters.
-        if postgis and self.geodetic and lookup_type != 'dwithin':
+       
+        if SpatialBackend.postgis and self.geodetic and lookup_type != 'dwithin' and option == 'spheroid':
+            # On PostGIS, by default `ST_distance_sphere` is used; but if the 
+            # accuracy of `ST_distance_spheroid` is needed than the spheroid 
+            # needs to be passed to the SQL stored procedure.
             return [gqn(self._spheroid), dist_param]
         else:
             return [dist_param]
@@ -119,12 +103,12 @@ class GeometryField(SpatialBackend.Field):
 
         # When the input is not a GEOS geometry, attempt to construct one
         # from the given string input.
-        if isinstance(geom, GEOSGeometry):
+        if isinstance(geom, SpatialBackend.Geometry):
             pass
         elif isinstance(geom, basestring):
             try:
-                geom = GEOSGeometry(geom)
-            except GEOSException:
+                geom = SpatialBackend.Geometry(geom)
+            except SpatialBackend.GeometryException:
                 raise ValueError('Could not create geometry from lookup value: %s' % str(value))
         else:
             raise TypeError('Cannot use parameter of `%s` type as lookup parameter.' % type(value))
@@ -148,8 +132,8 @@ class GeometryField(SpatialBackend.Field):
     def contribute_to_class(self, cls, name):
         super(GeometryField, self).contribute_to_class(cls, name)
         
-        # Setup for lazy-instantiated GEOSGeometry object.
-        setattr(cls, self.attname, GeometryProxy(GEOSGeometry, self))
+        # Setup for lazy-instantiated Geometry object.
+        setattr(cls, self.attname, GeometryProxy(SpatialBackend.Geometry, self))
 
     def get_db_prep_lookup(self, lookup_type, value):
         """
@@ -166,7 +150,7 @@ class GeometryField(SpatialBackend.Field):
             geom = self.get_geometry(value)
 
             # Getting the WHERE clause list and the associated params list. The params 
-            # list is populated with the Adaptor wrapping the GEOSGeometry for the 
+            # list is populated with the Adaptor wrapping the Geometry for the 
             # backend.  The WHERE clause list contains the placeholder for the adaptor
             # (e.g. any transformation SQL).
             where = [self.get_placeholder(geom)]
@@ -175,7 +159,7 @@ class GeometryField(SpatialBackend.Field):
             if isinstance(value, (tuple, list)):
                 if lookup_type in SpatialBackend.distance_functions:
                     # Getting the distance parameter in the units of the field.
-                    where += self.get_distance(value[1], lookup_type)
+                    where += self.get_distance(value[1:], lookup_type)
                 elif lookup_type in SpatialBackend.limited_where:
                     pass
                 else:
@@ -187,15 +171,15 @@ class GeometryField(SpatialBackend.Field):
 
     def get_db_prep_save(self, value):
         "Prepares the value for saving in the database."
-        if isinstance(value, GEOSGeometry):
+        if isinstance(value, SpatialBackend.Geometry):
             return SpatialBackend.Adaptor(value)
         elif value is None:
             return None
         else:
-            raise TypeError('Geometry Proxy should only return GEOSGeometry objects or None.')
+            raise TypeError('Geometry Proxy should only return Geometry objects or None.')
 
     def get_manipulator_field_objs(self):
-        "Using the WKTField (defined above) to be our manipulator."
+        "Using the WKTField (oldforms) to be our manipulator."
         return [WKTField]
 
 # The OpenGIS Geometry Type Fields
diff --git a/django/contrib/gis/db/models/manager.py b/django/contrib/gis/db/models/manager.py
index 8634dd9cee..4b010ac20c 100644
--- a/django/contrib/gis/db/models/manager.py
+++ b/django/contrib/gis/db/models/manager.py
@@ -7,20 +7,71 @@ class GeoManager(Manager):
     def get_query_set(self):
         return GeoQuerySet(model=self.model)
 
+    def area(self, *args, **kwargs):
+        return self.get_query_set().area(*args, **kwargs)
+
+    def centroid(self, *args, **kwargs):
+        return self.get_query_set().centroid(*args, **kwargs)
+
+    def difference(self, *args, **kwargs):
+        return self.get_query_set().difference(*args, **kwargs)
+
     def distance(self, *args, **kwargs):
         return self.get_query_set().distance(*args, **kwargs)
 
+    def envelope(self, *args, **kwargs):
+        return self.get_query_set().envelope(*args, **kwargs)
+
     def extent(self, *args, **kwargs):
         return self.get_query_set().extent(*args, **kwargs)
 
     def gml(self, *args, **kwargs):
         return self.get_query_set().gml(*args, **kwargs)
 
+    def intersection(self, *args, **kwargs):
+        return self.get_query_set().intersection(*args, **kwargs)
+
     def kml(self, *args, **kwargs):
         return self.get_query_set().kml(*args, **kwargs)
 
+    def length(self, *args, **kwargs):
+        return self.get_query_set().length(*args, **kwargs)
+
+    def make_line(self, *args, **kwargs):
+        return self.get_query_set().make_line(*args, **kwargs)
+    
+    def mem_size(self, *args, **kwargs):
+        return self.get_query_set().mem_size(*args, **kwargs)
+
+    def num_geom(self, *args, **kwargs):
+        return self.get_query_set().num_geom(*args, **kwargs)
+
+    def num_points(self, *args, **kwargs):
+        return self.get_query_set().num_points(*args, **kwargs)
+
+    def perimeter(self, *args, **kwargs):
+        return self.get_query_set().perimeter(*args, **kwargs)
+
+    def point_on_surface(self, *args, **kwargs):
+        return self.get_query_set().point_on_surface(*args, **kwargs)
+
+    def scale(self, *args, **kwargs):
+        return self.get_query_set().scale(*args, **kwargs)
+
+    def svg(self, *args, **kwargs):
+        return self.get_query_set().svg(*args, **kwargs)
+
+    def sym_difference(self, *args, **kwargs):
+        return self.get_query_set().sym_difference(*args, **kwargs)
+
     def transform(self, *args, **kwargs):
         return self.get_query_set().transform(*args, **kwargs)
 
+    def translate(self, *args, **kwargs):
+        return self.get_query_set().translate(*args, **kwargs)
+
     def union(self, *args, **kwargs):
         return self.get_query_set().union(*args, **kwargs)
+
+    def unionagg(self, *args, **kwargs):
+        return self.get_query_set().unionagg(*args, **kwargs)
diff --git a/django/contrib/gis/db/models/proxy.py b/django/contrib/gis/db/models/proxy.py
index 43e7dbe8ef..34276a6d63 100644
--- a/django/contrib/gis/db/models/proxy.py
+++ b/django/contrib/gis/db/models/proxy.py
@@ -1,7 +1,7 @@
 """
  The GeometryProxy object, allows for lazy-geometries.  The proxy uses
-  Python descriptors for instantiating and setting GEOS Geometry objects
-  corresponding to geographic model fields.
+ Python descriptors for instantiating and setting Geometry objects
+ corresponding to geographic model fields.
 
  Thanks to Robert Coup for providing this functionality (see #4322).
 """
@@ -31,8 +31,8 @@ class GeometryProxy(object):
         elif (geom_value is None) or (geom_value==''):
             geom = None
         else: 
-            # Otherwise, a GEOSGeometry object is built using the field's contents,
-            #  and the model's corresponding attribute is set.
+            # Otherwise, a Geometry object is built using the field's contents,
+            # and the model's corresponding attribute is set.
             geom = self._klass(geom_value)
             setattr(obj, self._field.attname, geom) 
         return geom 
diff --git a/django/contrib/gis/db/models/query.py b/django/contrib/gis/db/models/query.py
index 65b011c7a8..e779886c92 100644
--- a/django/contrib/gis/db/models/query.py
+++ b/django/contrib/gis/db/models/query.py
@@ -1,12 +1,12 @@
-from itertools import izip
 from django.core.exceptions import ImproperlyConfigured
 from django.db import connection
 from django.db.models.query import sql, QuerySet, Q
 
 from django.contrib.gis.db.backend import SpatialBackend
 from django.contrib.gis.db.models.fields import GeometryField, PointField
-from django.contrib.gis.db.models.sql import GeoQuery, GeoWhereNode
-from django.contrib.gis.geos import GEOSGeometry, Point
+from django.contrib.gis.db.models.sql import AreaField, DistanceField, GeomField, GeoQuery, GeoWhereNode
+from django.contrib.gis.measure import Area, Distance
+from django.contrib.gis.models import get_srid_info
 qn = connection.ops.quote_name
 
 # For backwards-compatibility; Q object should work just fine
@@ -28,174 +28,236 @@ class GeoQuerySet(QuerySet):
         super(GeoQuerySet, self).__init__(model=model, query=query)
         self.query = query or GeoQuery(self.model, connection)
 
-    def distance(self, *args, **kwargs):
+    def area(self, tolerance=0.05, **kwargs):
         """
-        Returns the distance from the given geographic field name to the
-        given geometry in a `distance` attribute on each element of the
-        GeoQuerySet.
+        Returns the area of the geographic field in an `area` attribute on 
+        each element of this GeoQuerySet.
         """
-        DISTANCE = SpatialBackend.distance
-        if not DISTANCE:
-            raise ImproperlyConfigured('Distance() stored proecedure not available.')
-
-        # Getting the geometry field and GEOSGeometry object to base distance
-        # calculations from.
-        nargs = len(args)
-        if nargs == 1:
-            field_name = None
-            geom = args[0]
-        elif nargs == 2:
-            field_name, geom = args
-        else:
-            raise ValueError('Maximum two arguments allowed for `distance` aggregate.')
-
-        # Getting the GeometryField and quoted column.
-        geo_field = self.query._geo_field(field_name)
-        if not geo_field:
-            raise TypeError('Distance output only available on GeometryFields.')
-        geo_col = self.query._field_column(geo_field)
-
-        # Using the field's get_db_prep_lookup() to get any needed
-        # transformation SQL -- we pass in a 'dummy' `contains`
-        # `distance_lte` lookup type.
-        where, params = geo_field.get_db_prep_lookup('distance_lte', (geom, 0))
+        # Peforming setup here rather than in `_spatial_attribute` so that
+        # we can get the units for `AreaField`.
+        procedure_args, geo_field = self._spatial_setup('area', field_name=kwargs.get('field_name', None))
+        s = {'procedure_args' : procedure_args,
+             'geo_field' : geo_field,
+             'setup' : False,
+             }
         if SpatialBackend.oracle:
-            # The `tolerance` keyword may be used for Oracle; the tolerance is 
-            # in meters -- a default of 5 centimeters is used.
-            tolerance = kwargs.get('tolerance', 0.05)
-            dist_select = {'distance' : '%s(%s, %s, %s)' % (DISTANCE, geo_col, where[0], tolerance)}
-        else:
-            if len(where) == 3:
-                # Spherical distance calculation was requested (b/c spheroid 
-                # parameter was attached) However, the PostGIS ST_distance_spheroid() 
-                # procedure may only do queries from point columns to point geometries
-                # some error checking is required.
-                if not isinstance(geo_field, PointField): 
-                    raise TypeError('Spherical distance calculation only supported on PointFields.')
-                if not isinstance(GEOSGeometry(buffer(params[0].wkb)), Point):
-                    raise TypeError('Spherical distance calculation only supported with Point Geometry parameters')
-
-                # Call to distance_spheroid() requires the spheroid as well.
-                dist_sql = '%s(%s, %s, %s)' % (SpatialBackend.distance_spheroid, geo_col, where[0], where[1])
+            s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
+            s['procedure_args']['tolerance'] = tolerance
+            s['select_field'] = AreaField('sq_m') # Oracle returns area in units of meters.
+        elif SpatialBackend.postgis:
+            if not geo_field.geodetic:
+                # Getting the area units of the geographic field.
+                s['select_field'] = AreaField(Area.unit_attname(geo_field._unit_name))
             else:
-                dist_sql = '%s(%s, %s)' % (DISTANCE, geo_col, where[0])
-            dist_select = {'distance' : dist_sql}
-        return self.extra(select=dist_select, select_params=params)
+                # TODO: Do we want to support raw number areas for geodetic fields?
+                raise Exception('Area on geodetic coordinate systems not supported.')
+        return self._spatial_attribute('area', s, **kwargs)
 
-    def extent(self, field_name=None):
+    def centroid(self, **kwargs):
         """
-        Returns the extent (aggregate) of the features in the GeoQuerySet.  The
-        extent will be returned as a 4-tuple, consisting of (xmin, ymin, xmax, ymax).
+        Returns the centroid of the geographic field in a `centroid`
+        attribute on each element of this GeoQuerySet.
         """
-        EXTENT = SpatialBackend.extent
-        if not EXTENT:
-            raise ImproperlyConfigured('Extent stored procedure not available.')
+        return self._geom_attribute('centroid', **kwargs)
 
-        # Getting the GeometryField and quoted column.
-        geo_field = self.query._geo_field(field_name)
-        if not geo_field:
-            raise TypeError('Extent information only available on GeometryFields.')
-        geo_col = self.query._field_column(geo_field)
+    def difference(self, geom, **kwargs):
+        """
+        Returns the spatial difference of the geographic field in a `difference`
+        attribute on each element of this GeoQuerySet.
+        """
+        return self._geomset_attribute('difference', geom, **kwargs)
 
-        # Constructing the query that will select the extent.
-        extent_sql = '%s(%s)' % (EXTENT, geo_col)
+    def distance(self, geom, **kwargs):
+        """
+        Returns the distance from the given geographic field name to the
+        given geometry in a `distance` attribute on each element of the
+        GeoQuerySet.
 
-        self.query.select = [GeomSQL(extent_sql)]
-        self.query.select_fields = [None]
-        try:
-            esql, params = self.query.as_sql()
-        except sql.datastructures.EmptyResultSet:
-            return None        
+        Keyword Arguments:
+         `spheroid`  => If the geometry field is geodetic and PostGIS is
+                        the spatial database, then the more accurate 
+                        spheroid calculation will be used instead of the
+                        quicker sphere calculation.
+                        
+         `tolerance` => Used only for Oracle. The tolerance is 
+                        in meters -- a default of 5 centimeters (0.05) 
+                        is used.
+        """
+        return self._distance_attribute('distance', geom, **kwargs)
 
-        # Getting a cursor, executing the query, and extracting the returned
-        # value from the extent function.
-        cursor = connection.cursor()
-        cursor.execute(esql, params)
-        box = cursor.fetchone()[0]
+    def envelope(self, **kwargs):
+        """
+        Returns a Geometry representing the bounding box of the 
+        Geometry field in an `envelope` attribute on each element of
+        the GeoQuerySet. 
+        """
+        return self._geom_attribute('envelope', **kwargs)
 
-        if box: 
-            # TODO: Parsing of BOX3D, Oracle support (patches welcome!)
-            #  Box text will be something like "BOX(-90.0 30.0, -85.0 40.0)"; 
-            #  parsing out and returning as a 4-tuple.
-            ll, ur = box[4:-1].split(',')
-            xmin, ymin = map(float, ll.split())
-            xmax, ymax = map(float, ur.split())
-            return (xmin, ymin, xmax, ymax)
-        else: 
-            return None
+    def extent(self, **kwargs):
+        """
+        Returns the extent (aggregate) of the features in the GeoQuerySet.  The
+        extent will be returned as a 4-tuple, consisting of (xmin, ymin, xmax, ymax).
+        """
+        convert_extent = None
+        if SpatialBackend.postgis:
+            def convert_extent(box, geo_field):
+                # TODO: Parsing of BOX3D, Oracle support (patches welcome!)
+                # Box text will be something like "BOX(-90.0 30.0, -85.0 40.0)"; 
+                # parsing out and returning as a 4-tuple.
+                ll, ur = box[4:-1].split(',')
+                xmin, ymin = map(float, ll.split())
+                xmax, ymax = map(float, ur.split())
+                return (xmin, ymin, xmax, ymax)
+        elif SpatialBackend.oracle:
+            def convert_extent(wkt, geo_field):
+                raise NotImplementedError
+        return self._spatial_aggregate('extent', convert_func=convert_extent, **kwargs)
 
-    def gml(self, field_name=None, precision=8, version=2):
+    def gml(self, precision=8, version=2, **kwargs):
         """
         Returns GML representation of the given field in a `gml` attribute
         on each element of the GeoQuerySet.
         """
-        # Is GML output supported?
-        ASGML = SpatialBackend.as_gml
-        if not ASGML:
-            raise ImproperlyConfigured('AsGML() stored procedure not available.')
- 
-        # Getting the GeometryField and quoted column.
-        geo_field = self.query._geo_field(field_name)
-        if not geo_field:
-            raise TypeError('GML output only available on GeometryFields.')
-        geo_col = self.query._field_column(geo_field)
-
-        if SpatialBackend.oracle:
-            gml_select = {'gml':'%s(%s)' % (ASGML, geo_col)}
-        elif SpatialBackend.postgis:
+        s = {'desc' : 'GML', 'procedure_args' : {'precision' : precision}}
+        if SpatialBackend.postgis:
             # PostGIS AsGML() aggregate function parameter order depends on the 
             # version -- uggh.
             major, minor1, minor2 = SpatialBackend.version
             if major >= 1 and (minor1 > 3 or (minor1 == 3 and minor2 > 1)):
-                gml_select = {'gml':'%s(%s,%s,%s)' % (ASGML, version, geo_col, precision)}
+                procedure_fmt = '%(version)s,%(geo_col)s,%(precision)s'
             else:
-                gml_select = {'gml':'%s(%s,%s,%s)' % (ASGML, geo_col, precision, version)}
+                procedure_fmt = '%(geo_col)s,%(precision)s,%(version)s'
+            s['procedure_args'] = {'precision' : precision, 'version' : version}
 
-        # Adding GML function call to SELECT part of the SQL.
-        return self.extra(select=gml_select)
+        return self._spatial_attribute('gml', s, **kwargs)
 
-    def kml(self, field_name=None, precision=8):
+    def intersection(self, geom, **kwargs):
         """
-        Returns KML representation of the given field name in a `kml`
-        attribute on each element of the GeoQuerySet.
+        Returns the spatial intersection of the Geometry field in
+        an `intersection` attribute on each element of this
+        GeoQuerySet.
         """
-        # Is KML output supported?
-        ASKML = SpatialBackend.as_kml
-        if not ASKML:
-            raise ImproperlyConfigured('AsKML() stored procedure not available.')
+        return self._geomset_attribute('intersection', geom, **kwargs)
 
-        # Getting the GeometryField and quoted column.
-        geo_field = self.query._geo_field(field_name)
-        if not geo_field:
-            raise TypeError('KML output only available on GeometryFields.')
+    def kml(self, **kwargs):
+        """
+        Returns KML representation of the geometry field in a `kml`
+        attribute on each element of this GeoQuerySet.
+        """
+        s = {'desc' : 'KML',
+             'procedure_fmt' : '%(geo_col)s,%(precision)s',
+             'procedure_args' : {'precision' : kwargs.pop('precision', 8)},
+             }
+        return self._spatial_attribute('kml', s, **kwargs)
 
-        geo_col = self.query._field_column(geo_field)
+    def length(self, **kwargs):
+        """
+        Returns the length of the geometry field as a `Distance` object
+        stored in a `length` attribute on each element of this GeoQuerySet.
+        """
+        return self._distance_attribute('length', None, **kwargs)
+
+    def make_line(self, **kwargs):
+        """
+        Creates a linestring from all of the PointField geometries in the
+        this GeoQuerySet and returns it.  This is a spatial aggregate
+        method, and thus returns a geometry rather than a GeoQuerySet.
+        """
+        kwargs['geo_field_type'] = PointField
+        kwargs['agg_field'] = GeometryField
+        return self._spatial_aggregate('make_line', **kwargs)
 
-        # Adding the AsKML function call to SELECT part of the SQL.
-        return self.extra(select={'kml':'%s(%s,%s)' % (ASKML, geo_col, precision)})
+    def mem_size(self, **kwargs):
+        """
+        Returns the memory size (number of bytes) that the geometry field takes
+        in a `mem_size` attribute  on each element of this GeoQuerySet.
+        """
+        return self._spatial_attribute('mem_size', {}, **kwargs)
 
-    def transform(self, field_name=None, srid=4326):
+    def num_geom(self, **kwargs):
+        """
+        Returns the number of geometries if the field is a
+        GeometryCollection or Multi* Field in a `num_geom`
+        attribute on each element of this GeoQuerySet; otherwise
+        the sets with None.
+        """
+        return self._spatial_attribute('num_geom', {}, **kwargs)
+
+    def num_points(self, **kwargs):
+        """
+        Returns the number of points in the first linestring in the 
+        Geometry field in a `num_points` attribute on each element of
+        this GeoQuerySet; otherwise sets with None.
+        """
+        return self._spatial_attribute('num_points', {}, **kwargs)
+
+    def perimeter(self, **kwargs):
+        """
+        Returns the perimeter of the geometry field as a `Distance` object
+        stored in a `perimeter` attribute on each element of this GeoQuerySet.
+        """
+        return self._distance_attribute('perimeter', None, **kwargs)
+
+    def point_on_surface(self, **kwargs):
+        """
+        Returns a Point geometry guaranteed to lie on the surface of the
+        Geometry field in a `point_on_surface` attribute on each element
+        of this GeoQuerySet; otherwise sets with None.
+        """
+        return self._geom_attribute('point_on_surface', **kwargs)
+
+    def scale(self, x, y, z=0.0, **kwargs):
+        """
+        Scales the geometry to a new size by multiplying the ordinates
+        with the given x,y,z scale factors.
+        """
+        s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
+             'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
+             'select_field' : GeomField(),
+             }
+        return self._spatial_attribute('scale', s, **kwargs)
+
+    def svg(self, **kwargs):
+        """
+        Returns SVG representation of the geographic field in a `svg`
+        attribute on each element of this GeoQuerySet.
+        """
+        s = {'desc' : 'SVG',
+             'procedure_fmt' : '%(geo_col)s,%(rel)s,%(precision)s',
+             'procedure_args' : {'rel' : int(kwargs.pop('relative', 0)),
+                                 'precision' : kwargs.pop('precision', 8)},
+             }
+        return self._spatial_attribute('svg', s, **kwargs)
+
+    def sym_difference(self, geom, **kwargs):
+        """
+        Returns the symmetric difference of the geographic field in a 
+        `sym_difference` attribute on each element of this GeoQuerySet.
+        """
+        return self._geomset_attribute('sym_difference', geom, **kwargs)
+
+    def translate(self, x, y, z=0.0, **kwargs):
+        """
+        Translates the geometry to a new location using the given numeric
+        parameters as offsets.
+        """
+        s = {'procedure_fmt' : '%(geo_col)s,%(x)s,%(y)s,%(z)s',
+             'procedure_args' : {'x' : x, 'y' : y, 'z' : z},
+             'select_field' : GeomField(),
+             }
+        return self._spatial_attribute('translate', s, **kwargs)
+
+    def transform(self, srid=4326, **kwargs):
         """
         Transforms the given geometry field to the given SRID.  If no SRID is
         provided, the transformation will default to using 4326 (WGS84).
         """
-        # Getting the geographic field.
-        TRANSFORM = SpatialBackend.transform
-        if not TRANSFORM:
-            raise ImproperlyConfigured('Transform stored procedure not available.')
+        if not isinstance(srid, (int, long)):
+            raise TypeError('An integer SRID must be provided.')
+        field_name = kwargs.get('field_name', None)
+        tmp, geo_field = self._spatial_setup('transform', field_name=field_name)
 
-        # `field_name` is first for backwards compatibility; but we want to
-        # be able to take integer srid as first parameter.
-        if isinstance(field_name, (int, long)):
-            srid = field_name
-            field_name = None
-
-        # Getting the GeometryField and quoted column.
-        geo_field = self.query._geo_field(field_name)
-        if not geo_field:
-            raise TypeError('%s() only available for GeometryFields' % TRANSFORM)
-        
-        # Getting the selection SQL for the given geograph
+        # Getting the selection SQL for the given geographic field.
         field_col = self._geocol_select(geo_field, field_name)
 
         # Why cascading substitutions? Because spatial backends like
@@ -206,63 +268,334 @@ class GeoQuerySet(QuerySet):
         
         # Setting the key for the field's column with the custom SELECT SQL to
         # override the geometry column returned from the database.
-        if SpatialBackend.oracle:
-            custom_sel = '%s(%s, %s)' % (TRANSFORM, geo_col, srid)
-            self.query.ewkt = srid
-        else:
-            custom_sel = '%s(%s, %s)' % (TRANSFORM, geo_col, srid)
+        custom_sel = '%s(%s, %s)' % (SpatialBackend.transform, geo_col, srid)
+        # TODO: Should we have this as an alias?
+        # custom_sel = '(%s(%s, %s)) AS %s' % (SpatialBackend.transform, geo_col, srid, qn(geo_field.name))
+        self.query.transformed_srid = srid # So other GeoQuerySet methods
         self.query.custom_select[geo_field] = custom_sel
         return self._clone()
 
-    def union(self, field_name=None, tolerance=0.0005):
+    def union(self, geom, **kwargs):
+        """
+        Returns the union of the geographic field with the given
+        Geometry in a `union` attribute on each element of this GeoQuerySet.
+        """
+        return self._geomset_attribute('union', geom, **kwargs)
+
+    def unionagg(self, **kwargs):
         """
         Performs an aggregate union on the given geometry field.  Returns
         None if the GeoQuerySet is empty.  The `tolerance` keyword is for
         Oracle backends only.
         """
-        # Making sure backend supports the Union stored procedure
-        UNION = SpatialBackend.union
-        if not UNION:
-            raise ImproperlyConfigured('Union stored procedure not available.')
+        kwargs['agg_field'] = GeometryField
+        return self._spatial_aggregate('unionagg', **kwargs)
 
-        # Getting the GeometryField and quoted column.
+    ### Private API -- Abstracted DRY routines. ###
+    def _spatial_setup(self, att, aggregate=False, desc=None, field_name=None, geo_field_type=None):
+        """
+        Performs set up for executing the spatial function.
+        """
+        # Does the spatial backend support this?
+        func = getattr(SpatialBackend, att, False)
+        if desc is None: desc = att
+        if not func: raise ImproperlyConfigured('%s stored procedure not available.' % desc)
+
+        # Initializing the procedure arguments. 
+        procedure_args = {'function' : func}
+        
+        # Is there a geographic field in the model to perform this 
+        # operation on?
         geo_field = self.query._geo_field(field_name)
         if not geo_field:
-            raise TypeError('Aggregate Union only available on GeometryFields.')
-        geo_col = self.query._field_column(geo_field)
+            raise TypeError('%s output only available on GeometryFields.' % func)
+
+        # If the `geo_field_type` keyword was used, then enforce that 
+        # type limitation.
+        if not geo_field_type is None and not isinstance(geo_field, geo_field_type): 
+            raise TypeError('"%s" stored procedures may only be called on %ss.' % (func, geo_field_type.__name__)) 
 
-        # Replacing the select with a call to the ST_Union stored procedure
-        #  on the geographic field column.
+        # Setting the procedure args.
+        procedure_args['geo_col'] = self._geocol_select(geo_field, field_name, aggregate)
+
+        return procedure_args, geo_field
+
+    def _spatial_aggregate(self, att, field_name=None, 
+                           agg_field=None, convert_func=None, 
+                           geo_field_type=None, tolerance=0.0005):
+        """
+        DRY routine for calling aggregate spatial stored procedures and
+        returning their result to the caller of the function.
+        """
+        # Constructing the setup keyword arguments.
+        setup_kwargs = {'aggregate' : True,
+                        'field_name' : field_name,
+                        'geo_field_type' : geo_field_type,
+                        }
+        procedure_args, geo_field = self._spatial_setup(att, **setup_kwargs)
+        
         if SpatialBackend.oracle:
-            union_sql = '%s' % SpatialBackend.select
-            union_sql = union_sql % ('%s(SDOAGGRTYPE(%s,%s))' % (UNION, geo_col, tolerance))
+            procedure_args['tolerance'] = tolerance
+            # Adding in selection SQL for Oracle geometry columns.
+            if agg_field is GeometryField: 
+                agg_sql = '%s' % SpatialBackend.select
+            else: 
+                agg_sql = '%s'
+            agg_sql =  agg_sql % ('%(function)s(SDOAGGRTYPE(%(geo_col)s,%(tolerance)s))' % procedure_args)
         else:
-            union_sql = '%s(%s)' % (UNION, geo_col)
+            agg_sql = '%(function)s(%(geo_col)s)' % procedure_args
+
+        # Wrapping our selection SQL in `GeomSQL` to bypass quoting, and
+        # specifying the type of the aggregate field.
+        self.query.select = [GeomSQL(agg_sql)]
+        self.query.select_fields = [agg_field]
 
-        # Only want the union SQL to be selected.
-        self.query.select = [GeomSQL(union_sql)]
-        self.query.select_fields = [GeometryField]
         try:
-            usql, params = self.query.as_sql()
+            # `asql` => not overriding `sql` module.
+            asql, params = self.query.as_sql()
         except sql.datastructures.EmptyResultSet:
-            return None
+            return None   
 
-        # Getting a cursor, executing the query.
+        # Getting a cursor, executing the query, and extracting the returned
+        # value from the aggregate function.
         cursor = connection.cursor()
-        cursor.execute(usql, params)
-        if SpatialBackend.oracle:
-            # On Oracle have to read out WKT from CLOB first.
-            clob = cursor.fetchone()[0]
-            if clob: u = clob.read()
-            else: u = None
+        cursor.execute(asql, params)
+        result = cursor.fetchone()[0]
+        
+        # If the `agg_field` is specified as a GeometryField, then autmatically
+        # set up the conversion function.
+        if agg_field is GeometryField and not callable(convert_func):
+            if SpatialBackend.postgis:
+                def convert_geom(hex, geo_field):
+                    if hex: return SpatialBackend.Geometry(hex)
+                    else: return None
+            elif SpatialBackend.oracle:
+                def convert_geom(clob, geo_field):
+                    if clob: return SpatialBackend.Geometry(clob.read(), geo_field._srid)
+                    else: return None
+            convert_func = convert_geom
+
+        # Returning the callback function evaluated on the result culled
+        # from the executed cursor.
+        if callable(convert_func):
+            return convert_func(result, geo_field)
+        else:
+            return result
+
+    def _spatial_attribute(self, att, settings, field_name=None, model_att=None):
+        """
+        DRY routine for calling a spatial stored procedure on a geometry column
+        and attaching its output as an attribute of the model.
+
+        Arguments:
+         att:
+          The name of the spatial attribute that holds the spatial
+          SQL function to call.
+
+         settings:
+          Dictonary of internal settings to customize for the spatial procedure. 
+
+        Public Keyword Arguments:
+
+         field_name:
+          The name of the geographic field to call the spatial
+          function on.  May also be a lookup to a geometry field
+          as part of a foreign key relation.
+
+         model_att:
+          The name of the model attribute to attach the output of
+          the spatial function to.
+        """
+        # Default settings.
+        settings.setdefault('desc', None)
+        settings.setdefault('geom_args', ())
+        settings.setdefault('geom_field', None)
+        settings.setdefault('procedure_args', {})
+        settings.setdefault('procedure_fmt', '%(geo_col)s')
+        settings.setdefault('select_params', [])
+
+        # Performing setup for the spatial column, unless told not to.
+        if settings.get('setup', True):
+            default_args, geo_field = self._spatial_setup(att, desc=settings['desc'], field_name=field_name)
+            for k, v in default_args.iteritems(): settings['procedure_args'].setdefault(k, v)
         else:
-            u = cursor.fetchone()[0]
+            geo_field = settings['geo_field']
+            
+        # The attribute to attach to the model.
+        if not isinstance(model_att, basestring): model_att = att
+
+        # Special handling for any argument that is a geometry.
+        for name in settings['geom_args']:
+            # Using the field's get_db_prep_lookup() to get any needed
+            # transformation SQL -- we pass in a 'dummy' `contains` lookup.
+            where, params = geo_field.get_db_prep_lookup('contains', settings['procedure_args'][name])
+            # Replacing the procedure format with that of any needed 
+            # transformation SQL.
+            old_fmt = '%%(%s)s' % name
+            new_fmt = where[0] % '%%s'
+            settings['procedure_fmt'] = settings['procedure_fmt'].replace(old_fmt, new_fmt)
+            settings['select_params'].extend(params)
+
+        # Getting the format for the stored procedure.
+        fmt = '%%(function)s(%s)' % settings['procedure_fmt']
         
-        if u: return GEOSGeometry(u)
-        else: return None
+        # If the result of this function needs to be converted.
+        if settings.get('select_field', False):
+            sel_fld = settings['select_field']
+            if isinstance(sel_fld, GeomField) and SpatialBackend.select:
+                self.query.custom_select[model_att] = SpatialBackend.select
+            self.query.extra_select_fields[model_att] = sel_fld
+
+        # Finally, setting the extra selection attribute with 
+        # the format string expanded with the stored procedure
+        # arguments.
+        return self.extra(select={model_att : fmt % settings['procedure_args']}, 
+                          select_params=settings['select_params'])
+
+    def _distance_attribute(self, func, geom=None, tolerance=0.05, spheroid=False, **kwargs):
+        """
+        DRY routine for GeoQuerySet distance attribute routines.
+        """
+        # Setting up the distance procedure arguments.
+        procedure_args, geo_field = self._spatial_setup(func, field_name=kwargs.get('field_name', None))
+
+        # If geodetic defaulting distance attribute to meters (Oracle and
+        # PostGIS spherical distances return meters).  Otherwise, use the
+        # units of the geometry field.
+        if geo_field.geodetic:
+            dist_att = 'm'
+        else:
+            dist_att = Distance.unit_attname(geo_field._unit_name)
+
+        # Shortcut booleans for what distance function we're using.
+        distance = func == 'distance'
+        length = func == 'length'
+        perimeter = func == 'perimeter'
+        if not (distance or length or perimeter): 
+            raise ValueError('Unknown distance function: %s' % func)
+
+        # The field's get_db_prep_lookup() is used to get any 
+        # extra distance parameters.  Here we set up the
+        # parameters that will be passed in to field's function.
+        lookup_params = [geom or 'POINT (0 0)', 0]
+
+        # If the spheroid calculation is desired, either by the `spheroid`
+        # keyword or wehn calculating the length of geodetic field, make
+        # sure the 'spheroid' distance setting string is passed in so we
+        # get the correct spatial stored procedure.            
+        if spheroid or (SpatialBackend.postgis and geo_field.geodetic and length): 
+            lookup_params.append('spheroid') 
+        where, params = geo_field.get_db_prep_lookup('distance_lte', lookup_params)
+
+        # The `geom_args` flag is set to true if a geometry parameter was 
+        # passed in.
+        geom_args = bool(geom)
+
+        if SpatialBackend.oracle:
+            if distance:
+                procedure_fmt = '%(geo_col)s,%(geom)s,%(tolerance)s'
+            elif length or perimeter:
+                procedure_fmt = '%(geo_col)s,%(tolerance)s'
+            procedure_args['tolerance'] = tolerance
+        else:
+            # Getting whether this field is in units of degrees since the field may have
+            # been transformed via the `transform` GeoQuerySet method.
+            if self.query.transformed_srid:
+                u, unit_name, s = get_srid_info(self.query.transformed_srid)
+                geodetic = unit_name in geo_field.geodetic_units
+            else:
+                geodetic = geo_field.geodetic
+            
+            if distance:
+                if self.query.transformed_srid:
+                    # Setting the `geom_args` flag to false because we want to handle
+                    # transformation SQL here, rather than the way done by default
+                    # (which will transform to the original SRID of the field rather
+                    #  than to what was transformed to).
+                    geom_args = False
+                    procedure_fmt = '%s(%%(geo_col)s, %s)' % (SpatialBackend.transform, self.query.transformed_srid)
+                    if geom.srid is None or geom.srid == self.query.transformed_srid:
+                        # If the geom parameter srid is None, it is assumed the coordinates 
+                        # are in the transformed units.  A placeholder is used for the
+                        # geometry parameter.
+                        procedure_fmt += ', %%s'
+                    else:
+                        # We need to transform the geom to the srid specified in `transform()`,
+                        # so wrapping the geometry placeholder in transformation SQL.
+                        procedure_fmt += ', %s(%%%%s, %s)' % (SpatialBackend.transform, self.query.transformed_srid)
+                else:
+                    # `transform()` was not used on this GeoQuerySet.
+                    procedure_fmt  = '%(geo_col)s,%(geom)s'
+
+                if geodetic:
+                    # Spherical distance calculation is needed (because the geographic
+                    # field is geodetic). However, the PostGIS ST_distance_sphere/spheroid() 
+                    # procedures may only do queries from point columns to point geometries
+                    # some error checking is required.
+                    if not isinstance(geo_field, PointField): 
+                        raise TypeError('Spherical distance calculation only supported on PointFields.')
+                    if not str(SpatialBackend.Geometry(buffer(params[0].wkb)).geom_type) == 'Point':
+                        raise TypeError('Spherical distance calculation only supported with Point Geometry parameters')
+                    # The `function` procedure argument needs to be set differently for
+                    # geodetic distance calculations.
+                    if spheroid:
+                        # Call to distance_spheroid() requires spheroid param as well.
+                        procedure_fmt += ',%(spheroid)s'
+                        procedure_args.update({'function' : SpatialBackend.distance_spheroid, 'spheroid' : where[1]})
+                    else:
+                        procedure_args.update({'function' : SpatialBackend.distance_sphere})
+            elif length or perimeter:
+                procedure_fmt = '%(geo_col)s'
+                if geodetic and length:
+                    # There's no `length_sphere`
+                    procedure_fmt += ',%(spheroid)s'
+                    procedure_args.update({'function' : SpatialBackend.length_spheroid, 'spheroid' : where[1]})
+
+        # Setting up the settings for `_spatial_attribute`.
+        s = {'select_field' : DistanceField(dist_att),
+             'setup' : False, 
+             'geo_field' : geo_field,
+             'procedure_args' : procedure_args,
+             'procedure_fmt' : procedure_fmt,
+             }
+        if geom_args: 
+            s['geom_args'] = ('geom',)
+            s['procedure_args']['geom'] = geom
+        elif geom:
+            # The geometry is passed in as a parameter because we handled
+            # transformation conditions in this routine.
+            s['select_params'] = [SpatialBackend.Adaptor(geom)]
+        return self._spatial_attribute(func, s, **kwargs)
+
+    def _geom_attribute(self, func, tolerance=0.05, **kwargs):
+        """
+        DRY routine for setting up a GeoQuerySet method that attaches a
+        Geometry attribute (e.g., `centroid`, `point_on_surface`).
+        """
+        s = {'select_field' : GeomField(),}
+        if SpatialBackend.oracle:
+            s['procedure_fmt'] = '%(geo_col)s,%(tolerance)s'
+            s['procedure_args'] = {'tolerance' : tolerance}
+        return self._spatial_attribute(func, s, **kwargs)
+                     
+    def _geomset_attribute(self, func, geom, tolerance=0.05, **kwargs):
+        """
+        DRY routine for setting up a GeoQuerySet method that attaches a
+        Geometry attribute and takes a Geoemtry parameter.  This is used
+        for geometry set-like operations (e.g., intersection, difference, 
+        union, sym_difference).
+        """
+        s = {'geom_args' : ('geom',),
+             'select_field' : GeomField(),
+             'procedure_fmt' : '%(geo_col)s,%(geom)s',
+             'procedure_args' : {'geom' : geom},
+            }
+        if SpatialBackend.oracle:
+            s['procedure_fmt'] += ',%(tolerance)s'
+            s['procedure_args']['tolerance'] = tolerance
+        return self._spatial_attribute(func, s, **kwargs)
 
-    # Private API utilities, subject to change.
-    def _geocol_select(self, geo_field, field_name):
+    def _geocol_select(self, geo_field, field_name, aggregate=False):
         """
         Helper routine for constructing the SQL to select the geographic
         column.  Takes into account if the geographic field is in a
@@ -274,6 +607,8 @@ class GeoQuerySet(QuerySet):
             # (e.g., if 'location__point' was given as the field name).
             self.query.add_select_related([field_name])
             self.query.pre_sql_setup()
+            # Can't non-aggregate and aggregate selections together.
+            if aggregate: self.query.aggregate = True 
             rel_table, rel_col = self.query.related_select_cols[self.query.related_select_fields.index(geo_field)]
             return self.query._field_column(geo_field, rel_table)
         else:
diff --git a/django/contrib/gis/db/models/sql/__init__.py b/django/contrib/gis/db/models/sql/__init__.py
index 8e87f6b2a2..4a66b41664 100644
--- a/django/contrib/gis/db/models/sql/__init__.py
+++ b/django/contrib/gis/db/models/sql/__init__.py
@@ -1,2 +1,2 @@
-from django.contrib.gis.db.models.sql.query import GeoQuery
+from django.contrib.gis.db.models.sql.query import AreaField, DistanceField, GeomField, GeoQuery
 from django.contrib.gis.db.models.sql.where import GeoWhereNode
diff --git a/django/contrib/gis/db/models/sql/query.py b/django/contrib/gis/db/models/sql/query.py
index 9cd691bea9..f1b4de546f 100644
--- a/django/contrib/gis/db/models/sql/query.py
+++ b/django/contrib/gis/db/models/sql/query.py
@@ -6,6 +6,7 @@ from django.db.models.fields.related import ForeignKey
 from django.contrib.gis.db.backend import SpatialBackend
 from django.contrib.gis.db.models.fields import GeometryField
 from django.contrib.gis.db.models.sql.where import GeoWhereNode
+from django.contrib.gis.measure import Area, Distance
 
 # Valid GIS query types.
 ALL_TERMS = sql.constants.QUERY_TERMS.copy()
@@ -24,14 +25,19 @@ class GeoQuery(sql.Query):
         # The following attributes are customized for the GeoQuerySet.
         # The GeoWhereNode and SpatialBackend classes contain backend-specific
         # routines and functions.
+        self.aggregate = False
         self.custom_select = {}
-        self.ewkt = None
+        self.transformed_srid = None
+        self.extra_select_fields = {}
 
     def clone(self, *args, **kwargs):
         obj = super(GeoQuery, self).clone(*args, **kwargs)
-        # Customized selection dictionary and EWKT flag have to be added to obj.
+        # Customized selection dictionary and transformed srid flag have
+        # to also be added to obj.
+        obj.aggregate = self.aggregate
         obj.custom_select = self.custom_select.copy()
-        obj.ewkt = self.ewkt
+        obj.transformed_srid = self.transformed_srid
+        obj.extra_select_fields = self.extra_select_fields.copy()
         return obj
 
     def get_columns(self, with_aliases=False):
@@ -49,7 +55,8 @@ class GeoQuery(sql.Query):
         """
         qn = self.quote_name_unless_alias
         qn2 = self.connection.ops.quote_name
-        result = ['(%s) AS %s' % (col, qn2(alias)) for alias, col in self.extra_select.iteritems()]
+        result = ['(%s) AS %s' % (self.get_extra_select_format(alias) % col, qn2(alias)) 
+                  for alias, col in self.extra_select.iteritems()]
         aliases = set(self.extra_select.keys())
         if with_aliases:
             col_aliases = aliases.copy()
@@ -80,17 +87,18 @@ class GeoQuery(sql.Query):
             result.extend(cols)
             aliases.update(new_aliases)
         # This loop customized for GeoQuery.
-        for (table, col), field in izip(self.related_select_cols, self.related_select_fields):
-            r = self.get_field_select(field, table)
-            if with_aliases and col in col_aliases:
-                c_alias = 'Col%d' % len(col_aliases)
-                result.append('%s AS %s' % (r, c_alias))
-                aliases.add(c_alias)
-                col_aliases.add(c_alias)
-            else:
-                result.append(r)
-                aliases.add(r)
-                col_aliases.add(col)
+        if not self.aggregate:
+            for (table, col), field in izip(self.related_select_cols, self.related_select_fields):
+                r = self.get_field_select(field, table)
+                if with_aliases and col in col_aliases:
+                    c_alias = 'Col%d' % len(col_aliases)
+                    result.append('%s AS %s' % (r, c_alias))
+                    aliases.add(c_alias)
+                    col_aliases.add(c_alias)
+                else:
+                    result.append(r)
+                    aliases.add(r)
+                    col_aliases.add(col)
 
         self._select_aliases = aliases
         return result
@@ -139,7 +147,51 @@ class GeoQuery(sql.Query):
                     col_aliases.add(field.column)
         return result, aliases
 
+    def resolve_columns(self, row, fields=()):
+        """
+        This routine is necessary so that distances and geometries returned
+        from extra selection SQL get resolved appropriately into Python 
+        objects.
+        """
+        values = []
+        aliases = self.extra_select.keys()
+        index_start = len(aliases)
+        values = [self.convert_values(v, self.extra_select_fields.get(a, None)) 
+                  for v, a in izip(row[:index_start], aliases)]
+        if SpatialBackend.oracle:
+            # This is what happens normally in Oracle's `resolve_columns`.
+            for value, field in izip(row[index_start:], fields):
+                values.append(self.convert_values(value, field))
+        else:
+            values.extend(row[index_start:])
+        return values
+
+    def convert_values(self, value, field):
+        """
+        Using the same routines that Oracle does we can convert our
+        extra selection objects into Geometry and Distance objects.
+        TODO: Laziness.
+        """
+        if SpatialBackend.oracle:
+            # Running through Oracle's first.
+            value = super(GeoQuery, self).convert_values(value, field)
+        if isinstance(field, DistanceField):
+            # Using the field's distance attribute, can instantiate
+            # `Distance` with the right context.
+            value = Distance(**{field.distance_att : value})
+        elif isinstance(field, AreaField):
+            value = Area(**{field.area_att : value})
+        elif isinstance(field, GeomField):
+            value = SpatialBackend.Geometry(value)
+        return value
+
     #### Routines unique to GeoQuery ####
+    def get_extra_select_format(self, alias):
+        sel_fmt = '%s'
+        if alias in self.custom_select:
+            sel_fmt = sel_fmt % self.custom_select[alias]
+        return sel_fmt
+
     def get_field_select(self, fld, alias=None):
         """
         Returns the SELECT SQL string for the given field.  Figures out
@@ -173,8 +225,8 @@ class GeoQuery(sql.Query):
             # the SRID is prefixed to the returned WKT to ensure that the
             # transformed geometries have an SRID different than that of the
             # field -- this is only used by `transform` for Oracle backends.
-            if self.ewkt and SpatialBackend.oracle:
-                sel_fmt = "'SRID=%d;'||%s" % (self.ewkt, sel_fmt)
+            if self.transformed_srid and SpatialBackend.oracle:
+                sel_fmt = "'SRID=%d;'||%s" % (self.transformed_srid, sel_fmt)
         else:
             sel_fmt = '%s'
         return sel_fmt
@@ -188,8 +240,8 @@ class GeoQuery(sql.Query):
         Related model field strings like 'address__point', may also be 
         used.
 
-        If a GeometryField exists according to the given name
-        parameter it will be returned, otherwise returns False.
+        If a GeometryField exists according to the given name parameter 
+        it will be returned, otherwise returns False.
         """
         if isinstance(name_param, basestring):
             # This takes into account the situation where the name is a 
@@ -242,3 +294,17 @@ class GeoQuery(sql.Query):
             # Otherwise, check by the given field name -- which may be
             # a lookup to a _related_ geographic field.
             return self._check_geo_field(self.model, field_name)
+
+### Field Classes for `convert_values` ####
+class AreaField(object):
+    def __init__(self, area_att):
+        self.area_att = area_att
+
+class DistanceField(object):
+    def __init__(self, distance_att):
+        self.distance_att = distance_att
+
+# Rather than use GeometryField (which requires a SQL query
+# upon instantiation), use this lighter weight class.
+class GeomField(object): 
+    pass
diff --git a/django/contrib/gis/db/models/sql/where.py b/django/contrib/gis/db/models/sql/where.py
index 3c37232cfd..d9c75eaec3 100644
--- a/django/contrib/gis/db/models/sql/where.py
+++ b/django/contrib/gis/db/models/sql/where.py
@@ -1,5 +1,5 @@
 from django.db.models.sql.where import WhereNode
-from django.contrib.gis.db.backend import get_geo_where_clause, GIS_TERMS
+from django.contrib.gis.db.backend import get_geo_where_clause, SpatialBackend
 
 class GeoWhereNode(WhereNode):
     """
@@ -9,7 +9,7 @@ class GeoWhereNode(WhereNode):
     def make_atom(self, child, qn):
         table_alias, name, field, lookup_type, value = child
         if hasattr(field, '_geom'):
-            if lookup_type in GIS_TERMS:
+            if lookup_type in SpatialBackend.gis_terms:
                 # Getting the geographic where clause; substitution parameters
                 # will be populated in the GeoFieldSQL object returned by the
                 # GeometryField.
diff --git a/django/contrib/gis/measure.py b/django/contrib/gis/measure.py
index 5af5ab40f6..ea2e57c1ca 100644
--- a/django/contrib/gis/measure.py
+++ b/django/contrib/gis/measure.py
@@ -30,14 +30,60 @@
 Distance and Area objects to allow for sensible and convienient calculation 
 and conversions.
 
-Author: Robert Coup
+Author: Robert Coup, Justin Bronn
 
 Inspired by GeoPy (http://exogen.case.edu/projects/geopy/)
 and Geoff Biggs' PhD work on dimensioned units for robotics.
 """
+__all__ = ['A', 'Area', 'D', 'Distance']
 from decimal import Decimal
 
-class Distance(object):
+class MeasureBase(object):
+    def default_units(self, kwargs):
+        """
+        Return the unit value and the the default units specified
+        from the given keyword arguments dictionary.
+        """
+        val = 0.0
+        for unit, value in kwargs.iteritems():
+            if unit in self.UNITS:
+                val += self.UNITS[unit] * value
+                default_unit = unit
+            elif unit in self.ALIAS:
+                u = self.ALIAS[unit]
+                val += self.UNITS[u] * value
+                default_unit = u
+            else:
+                lower = unit.lower()
+                if lower in self.UNITS:
+                    val += self.UNITS[lower] * value
+                    default_unit = lower
+                elif lower in self.LALIAS:
+                    u = self.LALIAS[lower]
+                    val += self.UNITS[u] * value
+                    default_unit = u
+                else:
+                    raise AttributeError('Unknown unit type: %s' % unit)
+        return val, default_unit
+
+    @classmethod
+    def unit_attname(cls, unit_str):
+        """
+        Retrieves the unit attribute name for the given unit string.  
+        For example, if the given unit string is 'metre', 'm' would be returned.
+        An exception is raised if an attribute cannot be found.
+        """
+        lower = unit_str.lower()
+        if unit_str in cls.UNITS:
+            return unit_str
+        elif lower in cls.UNITS:
+            return lower
+        elif lower in cls.LALIAS:
+            return cls.LALIAS[lower]
+        else:
+            raise Exception('Could not find a unit keyword associated with "%s"' % unit_str)
+
+class Distance(MeasureBase):
     UNITS = {
         'chain' : 20.1168,
         'chain_benoit' : 20.116782,
@@ -53,7 +99,6 @@ class Distance(object):
         'fathom' :  1.8288,
         'ft': 0.3048,
         'german_m' : 1.0000135965,
-        'grad' : 0.0157079632679,
         'gold_coast_ft' : 0.304799710181508,
         'indian_yd' : 0.914398530744,
         'in' : 0.0254,
@@ -92,9 +137,10 @@ class Distance(object):
         'British chain (Sears 1922)' : 'british_chain_sears',
         'British chain (Sears 1922 truncated)' : 'british_chain_sears_truncated',
         'British foot (Sears 1922)' : 'british_ft',
+        'British foot' : 'british_ft',
         'British yard (Sears 1922)' : 'british_yd',
+        'British yard' : 'british_yd',
         "Clarke's Foot" : 'clarke_ft',
-        "Clarke's foot" : 'clarke_ft',
         "Clarke's link" : 'clarke_link',
         'Chain (Benoit)' : 'chain_benoit',
         'Chain (Sears)' : 'chain_sears',
@@ -111,33 +157,11 @@ class Distance(object):
         'Yard (Indian)' : 'indian_yd',
         'Yard (Sears)' : 'sears_yd'
         }
-    REV_ALIAS = dict((value, key) for key, value in ALIAS.items())
+    LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()])
 
     def __init__(self, default_unit=None, **kwargs):
         # The base unit is in meters.
-        self.m = 0.0
-        self._default_unit = 'm'
-        
-        for unit,value in kwargs.items():
-            if unit in self.UNITS:
-                self.m += self.UNITS[unit] * value
-                self._default_unit = unit
-            elif unit in self.ALIAS:
-                u = self.ALIAS[unit]
-                self.m += self.UNITS[u] * value
-                self._default_unit = u
-            else:
-                lower = unit.lower()
-                if lower in self.UNITS:
-                    self.m += self.UNITS[lower] * value
-                    self._default_unit = lower
-                elif lower in self.ALIAS:
-                    u = self.ALIAS[lower]
-                    self.m += self.UNITS[u] * value
-                    self._default_unit = u
-                else:
-                    raise AttributeError('Unknown unit type: %s' % unit)
-
+        self.m, self._default_unit = self.default_units(kwargs)
         if default_unit and isinstance(default_unit, str):
             self._default_unit = default_unit
     
@@ -216,49 +240,15 @@ class Distance(object):
     def __nonzero__(self):
         return bool(self.m)
 
-    @classmethod
-    def unit_attname(cls, unit_str):
-        """
-        Retrieves the unit attribute name for the given unit string.  
-        For example, if the given unit string is 'metre', 'm' would be returned.  
-        An exception is raised if an attribute cannot be found.
-        """
-        lower = unit_str.lower()
-
-        if unit_str in cls.UNITS:
-            return unit_str
-        elif lower in cls.UNITS:
-            return lower
-        elif unit_str in cls.ALIAS:
-            return cls.ALIAS[unit_str]
-        elif lower in cls.ALIAS:
-            return cls.ALIAS[lower]
-        else:
-            raise Exception('Could not find a unit keyword associated with "%s"' % unit_str)
-
-class Area(object):
-    # TODO: Add units from above.
-    UNITS = {
-        'sq_m': 1.0,
-        'sq_km': 1000000.0,
-        'sq_mi': 2589988.110336,
-        'sq_ft': 0.09290304,
-        'sq_yd': 0.83612736,
-        'sq_nm': 3429904.0,
-    }
+class Area(MeasureBase):
+    # Getting the square units values and the alias dictionary.
+    UNITS = dict([('sq_%s' % k, v ** 2) for k, v in Distance.UNITS.items()])
+    ALIAS = dict([(k, 'sq_%s' % v) for k, v in Distance.ALIAS.items()])
+    LALIAS = dict([(k.lower(), v) for k, v in ALIAS.items()])
 
     def __init__(self, default_unit=None, **kwargs):
-        self.sq_m = 0.0
-        self._default_unit = 'sq_m'
-        
-        for unit,value in kwargs.items():
-            if unit in self.UNITS:
-                self.sq_m += self.UNITS[unit] * value
-                self._default_unit = unit
-            else:
-                raise AttributeError('Unknown unit type: ' + unit)
-
-        if default_unit:
+        self.sq_m, self._default_unit = self.default_units(kwargs)
+        if default_unit and isinstance(default_unit, str):
             self._default_unit = default_unit
     
     def __getattr__(self, name):
@@ -333,7 +323,6 @@ class Area(object):
 
     def __nonzero__(self):
         return bool(self.sq_m)
-
         
 # Shortcuts
 D = Distance
diff --git a/django/contrib/gis/models.py b/django/contrib/gis/models.py
index 9d923760a3..8bf8ef4964 100644
--- a/django/contrib/gis/models.py
+++ b/django/contrib/gis/models.py
@@ -209,9 +209,54 @@ class SpatialRefSysMixin(object):
             return unicode(self.wkt)
 
 # The SpatialRefSys and GeometryColumns models
+_srid_info = True
 if settings.DATABASE_ENGINE == 'postgresql_psycopg2':
     from django.contrib.gis.db.backend.postgis.models import GeometryColumns, SpatialRefSys
 elif settings.DATABASE_ENGINE == 'oracle':
     from django.contrib.gis.db.backend.oracle.models import GeometryColumns, SpatialRefSys
 else:
-    pass
+    _srid_info = False
+
+if _srid_info:
+    def get_srid_info(srid):
+        """
+        Returns the units, unit name, and spheroid WKT associated with the
+        given SRID from the `spatial_ref_sys` (or equivalent) spatial database
+        table.  We use a database cursor to execute the query because this
+        function is used when it is not possible to use the ORM (for example,
+        during field initialization).
+        """
+        from django.db import connection
+        # Getting the spatial reference WKT associated with the SRID from the
+        # `spatial_ref_sys` (or equivalent) spatial database table.
+        #
+        # The following doesn't work: SpatialRefSys.objects.get(srid=srid)
+        # Why?  `syncdb` fails to recognize installed geographic models when there's
+        # an ORM query instantiated within a model field.
+        cur = connection.cursor()
+        qn = connection.ops.quote_name
+        stmt = 'SELECT %(table)s.%(wkt_col)s FROM %(table)s WHERE (%(table)s.%(srid_col)s = %(srid)s)'
+        stmt = stmt % {'table' : qn(SpatialRefSys._meta.db_table),
+                       'wkt_col' : qn(SpatialRefSys.wkt_col()),
+                       'srid_col' : qn('srid'),
+                       'srid' : srid,
+                       }
+        cur.execute(stmt)
+        srs_wkt = cur.fetchone()[0]
+        if srs_wkt is None:
+            raise ValueError('Failed to find Spatial Reference System entry corresponding to SRID=%s' % srid)
+
+        # Getting metadata associated with the spatial reference system identifier.
+        # Specifically, getting the unit information and spheroid information 
+        # (both required for distance queries).
+        unit, unit_name = SpatialRefSys.get_units(srs_wkt)
+        spheroid = SpatialRefSys.get_spheroid(srs_wkt)
+        return unit, unit_name, spheroid
+else:
+    def get_srid_info(srid):
+        """
+        Dummy routine for the backends that do not have the OGC required
+        spatial metadata tables (like MySQL).
+        """
+        return None, None, None
+   
diff --git a/django/contrib/gis/tests/__init__.py b/django/contrib/gis/tests/__init__.py
index b3afe9baa7..44465f4f23 100644
--- a/django/contrib/gis/tests/__init__.py
+++ b/django/contrib/gis/tests/__init__.py
@@ -11,7 +11,7 @@ from django.conf import settings
 if not settings._target: settings.configure()
 
 # Tests that require use of a spatial database (e.g., creation of models)
-test_models = ['geoapp', 'relatedapp']
+test_models = ['geoapp',]
 
 # Tests that do not require setting up and tearing down a spatial database.
 test_suite_names = [
@@ -20,11 +20,14 @@ test_suite_names = [
 ]
 if HAS_GDAL:
     if oracle:
-        # TODO: There is a problem with the `syncdb` SQL for the LayerMapping
-        # tests on Oracle.
-        test_models += ['distapp']
-    elif postgis:
+        # TODO: There's a problem with `select_related` and GeoQuerySet on
+        # Oracle -- e.g., GeoModel.objects.distance(geom, field_name='fk__point')
+        # doesn't work so we don't test `relatedapp`.
         test_models += ['distapp', 'layermap']
+    elif postgis:
+        test_models += ['distapp', 'layermap', 'relatedapp']
+    elif mysql:
+        test_models += ['relatedapp']
 
     test_suite_names += [
         'test_gdal_driver',
diff --git a/django/contrib/gis/tests/distapp/data.py b/django/contrib/gis/tests/distapp/data.py
index 6ccee717c6..fefe313905 100644
--- a/django/contrib/gis/tests/distapp/data.py
+++ b/django/contrib/gis/tests/distapp/data.py
@@ -11,16 +11,23 @@ au_cities = (('Wollongong', 150.902, -34.4245),
              ('Hillsdale', 151.231341, -33.952685),
              )
 
-stx_cities = (('Downtown Houston', 951640.547328, 4219369.26172),
-              ('West University Place', 943547.922328, 4213623.65345),
-              ('Southside Place', 944704.643307, 4212768.87617),
-              ('Bellaire', 942595.669129, 4212686.72583),
-              ('Pearland', 959674.616506, 4197465.6526),
-              ('Galveston', 1008151.16007, 4170027.47655),
-              ('Sealy', 874859.286808, 4219186.8641),
-              ('San Antonio', 649173.910483, 4176413.27786),
-              ('Round Rock', 726846.03695, 4297160.99715),
-              ('Saint Hedwig', 677644.649952, 4175467.06744),
+stx_cities = (('Downtown Houston', -95.363151, 29.763374),
+              ('West University Place', -95.448601, 29.713803),
+              ('Southside Place', -95.436920, 29.705777),
+              ('Bellaire', -95.458732, 29.705614),
+              ('Pearland', -95.287303, 29.563568),
+              ('Galveston', -94.797489, 29.301336),
+              ('Sealy', -96.156952, 29.780918),
+              ('San Antonio', -98.493183, 29.424170),
+              ('Saint Hedwig', -98.199820, 29.414197),
               )
 
+# Data from U.S. Census ZCTA cartographic boundary file for Texas (`zt48_d00.shp`).
+stx_zips = (('77002', 'POLYGON ((-95.365015 29.772327, -95.362415 29.772327, -95.360915 29.771827, -95.354615 29.771827, -95.351515 29.772527, -95.350915 29.765327, -95.351015 29.762436, -95.350115 29.760328, -95.347515 29.758528, -95.352315 29.753928, -95.356415 29.756328, -95.358215 29.754028, -95.360215 29.756328, -95.363415 29.757128, -95.364014 29.75638, -95.363415 29.753928, -95.360015 29.751828, -95.361815 29.749528, -95.362715 29.750028, -95.367516 29.744128, -95.369316 29.745128, -95.373916 29.744128, -95.380116 29.738028, -95.387916 29.727929, -95.388516 29.729629, -95.387916 29.732129, -95.382916 29.737428, -95.376616 29.742228, -95.372616 29.747228, -95.378601 29.750846, -95.378616 29.752028, -95.378616 29.754428, -95.376016 29.754528, -95.374616 29.759828, -95.373616 29.761128, -95.371916 29.763928, -95.372316 29.768727, -95.365884 29.76791, -95.366015 29.767127, -95.358715 29.765327, -95.358615 29.766327, -95.359115 29.767227, -95.360215 29.767027, -95.362783 29.768267, -95.365315 29.770527, -95.365015 29.772327))'),
+            ('77005', 'POLYGON ((-95.447918 29.727275, -95.428017 29.728729, -95.421117 29.729029, -95.418617 29.727629, -95.418517 29.726429, -95.402117 29.726629, -95.402117 29.725729, -95.395316 29.725729, -95.391916 29.726229, -95.389716 29.725829, -95.396517 29.715429, -95.397517 29.715929, -95.400917 29.711429, -95.411417 29.715029, -95.418417 29.714729, -95.418317 29.70623, -95.440818 29.70593, -95.445018 29.70683, -95.446618 29.70763, -95.447418 29.71003, -95.447918 29.727275))'),
+            ('77025', 'POLYGON ((-95.418317 29.70623, -95.414717 29.706129, -95.414617 29.70533, -95.418217 29.70533, -95.419817 29.69533, -95.419484 29.694196, -95.417166 29.690901, -95.414517 29.69433, -95.413317 29.69263, -95.412617 29.68973, -95.412817 29.68753, -95.414087 29.685055, -95.419165 29.685428, -95.421617 29.68513, -95.425717 29.67983, -95.425017 29.67923, -95.424517 29.67763, -95.427418 29.67763, -95.438018 29.664631, -95.436713 29.664411, -95.440118 29.662231, -95.439218 29.661031, -95.437718 29.660131, -95.435718 29.659731, -95.431818 29.660331, -95.441418 29.656631, -95.441318 29.656331, -95.441818 29.656131, -95.441718 29.659031, -95.441118 29.661031, -95.446718 29.656431, -95.446518 29.673431, -95.446918 29.69013, -95.447418 29.71003, -95.446618 29.70763, -95.445018 29.70683, -95.440818 29.70593, -95.418317 29.70623))'),
+            ('77401', 'POLYGON ((-95.447918 29.727275, -95.447418 29.71003, -95.446918 29.69013, -95.454318 29.68893, -95.475819 29.68903, -95.475819 29.69113, -95.484419 29.69103, -95.484519 29.69903, -95.480419 29.70133, -95.480419 29.69833, -95.474119 29.69833, -95.474119 29.70453, -95.472719 29.71283, -95.468019 29.71293, -95.468219 29.720229, -95.464018 29.720229, -95.464118 29.724529, -95.463018 29.725929, -95.459818 29.726129, -95.459918 29.720329, -95.451418 29.720429, -95.451775 29.726303, -95.451318 29.727029, -95.447918 29.727275))'),
+            )
 
+interstates = (('I-25', 'LINESTRING(-104.4780170766108 36.66698791870694, -104.4468522338495 36.79925409393386, -104.46212692626 36.9372149776075, -104.5126119783768 37.08163268820887, -104.5247764602161 37.29300499892048, -104.7084397427668 37.49150259925398, -104.8126599016282 37.69514285621863, -104.8452887035466 37.87613395659479, -104.7160169341003 38.05951763337799, -104.6165437927668 38.30432045855106, -104.6437227858174 38.53979986564737, -104.7596170387259 38.7322907594295, -104.8380078676822 38.89998460604341, -104.8501253693506 39.09980189213358, -104.8791648316464 39.24368776457503, -104.8635041274215 39.3785278162751, -104.8894471170052 39.5929228239605, -104.9721242843344 39.69528482419685, -105.0112104500356 39.7273080432394, -105.0010368577104 39.76677607811571, -104.981835619 39.81466504121967, -104.9858891550477 39.88806911250832, -104.9873548059578 39.98117234571016, -104.9766220487419 40.09796423450692, -104.9818565932953 40.36056530662884, -104.9912746373997 40.74904484447656)'),
+               )
diff --git a/django/contrib/gis/tests/distapp/models.py b/django/contrib/gis/tests/distapp/models.py
index 836b769e61..f23b277fea 100644
--- a/django/contrib/gis/tests/distapp/models.py
+++ b/django/contrib/gis/tests/distapp/models.py
@@ -7,6 +7,13 @@ class SouthTexasCity(models.Model):
     objects = models.GeoManager()
     def __unicode__(self): return self.name
 
+class SouthTexasCityFt(models.Model):
+    "Same City model as above, but U.S. survey feet are the units."
+    name = models.CharField(max_length=30)
+    point = models.PointField(srid=2278)
+    objects = models.GeoManager()
+    def __unicode__(self): return self.name
+
 class AustraliaCity(models.Model):
     "City model for Australia, using WGS84."
     name = models.CharField(max_length=30)
@@ -14,7 +21,22 @@ class AustraliaCity(models.Model):
     objects = models.GeoManager()
     def __unicode__(self): return self.name
 
-#class County(models.Model):
-#    name = models.CharField(max_length=30)
-#    mpoly = models.MultiPolygonField(srid=32140)
-#    objects = models.GeoManager()
+class CensusZipcode(models.Model):
+    "Model for a few South Texas ZIP codes (in original Census NAD83)."
+    name = models.CharField(max_length=5)
+    poly = models.PolygonField(srid=4269)
+    objects = models.GeoManager()
+
+class SouthTexasZipcode(models.Model):
+    "Model for a few South Texas ZIP codes."
+    name = models.CharField(max_length=5)
+    poly = models.PolygonField(srid=32140)
+    objects = models.GeoManager()
+    def __unicode__(self): return self.name
+
+class Interstate(models.Model):
+    "Geodetic model for U.S. Interstates."
+    name = models.CharField(max_length=10)
+    line = models.LineStringField()
+    objects = models.GeoManager()
+    def __unicode__(self): return self.name
diff --git a/django/contrib/gis/tests/distapp/tests.py b/django/contrib/gis/tests/distapp/tests.py
index d1fe83ebc5..53bcf9d42d 100644
--- a/django/contrib/gis/tests/distapp/tests.py
+++ b/django/contrib/gis/tests/distapp/tests.py
@@ -1,14 +1,15 @@
 import os, unittest
 from decimal import Decimal
 
+from django.db.models import Q
 from django.contrib.gis.gdal import DataSource
 from django.contrib.gis.geos import GEOSGeometry, Point, LineString
 from django.contrib.gis.measure import D # alias for Distance
 from django.contrib.gis.db.models import GeoQ
-from django.contrib.gis.tests.utils import oracle
+from django.contrib.gis.tests.utils import oracle, postgis, no_oracle
 
-from models import SouthTexasCity, AustraliaCity
-from data import au_cities, stx_cities
+from models import AustraliaCity, Interstate, SouthTexasCity, SouthTexasCityFt, CensusZipcode, SouthTexasZipcode
+from data import au_cities, interstates, stx_cities, stx_zips
 
 class DistanceTest(unittest.TestCase):
 
@@ -20,41 +21,64 @@ class DistanceTest(unittest.TestCase):
     # Another one for Australia
     au_pnt = GEOSGeometry('POINT (150.791 -34.4919)', 4326)
 
-    def get_cities(self, qs):
+    def get_names(self, qs):
         cities = [c.name for c in qs]
         cities.sort()
         return cities
 
     def test01_init(self):
         "Initialization of distance models."
-        
-        def load_cities(city_model, srid, data_tup):
+
+        # Loading up the cities.
+        def load_cities(city_model, data_tup):
             for name, x, y in data_tup:
-                c = city_model(name=name, point=Point(x, y, srid=srid))
+                c = city_model(name=name, point=Point(x, y, srid=4326))
                 c.save()
         
-        load_cities(SouthTexasCity, 32140, stx_cities)
-        load_cities(AustraliaCity, 4326, au_cities)
+        load_cities(SouthTexasCity, stx_cities)
+        load_cities(SouthTexasCityFt, stx_cities)
+        load_cities(AustraliaCity, au_cities)
 
-        self.assertEqual(10, SouthTexasCity.objects.count())
+        self.assertEqual(9, SouthTexasCity.objects.count())
+        self.assertEqual(9, SouthTexasCityFt.objects.count())
         self.assertEqual(11, AustraliaCity.objects.count())
+        
+        # Loading up the South Texas Zip Codes.
+        for name, wkt in stx_zips:
+            poly = GEOSGeometry(wkt, srid=4269)
+            SouthTexasZipcode(name=name, poly=poly).save()
+            CensusZipcode(name=name, poly=poly).save()
+        self.assertEqual(4, SouthTexasZipcode.objects.count())
+        self.assertEqual(4, CensusZipcode.objects.count())
+
+        # Loading up the Interstates.
+        for name, wkt in interstates:
+            Interstate(name=name, line=GEOSGeometry(wkt, srid=4326)).save()
+        self.assertEqual(1, Interstate.objects.count())
 
     def test02_dwithin(self):
         "Testing the `dwithin` lookup type."
         # Distances -- all should be equal (except for the
         # degree/meter pair in au_cities, that's somewhat
         # approximate).
-        tx_dists = [7000, D(km=7), D(mi=4.349)]
+        tx_dists = [(7000, 22965.83), D(km=7), D(mi=4.349)]
         au_dists = [(0.5, 32000), D(km=32), D(mi=19.884)]
         
         # Expected cities for Australia and Texas.
         tx_cities = ['Downtown Houston', 'Southside Place']
         au_cities = ['Mittagong', 'Shellharbour', 'Thirroul', 'Wollongong']
 
+        # Performing distance queries on two projected coordinate systems one
+        # with units in meters and the other in units of U.S. survey feet.
         for dist in tx_dists:
-            qs = SouthTexasCity.objects.filter(point__dwithin=(self.stx_pnt, dist))
-            self.assertEqual(tx_cities, self.get_cities(qs))
+            if isinstance(dist, tuple): dist1, dist2 = dist
+            else: dist1 = dist2 = dist
+            qs1 = SouthTexasCity.objects.filter(point__dwithin=(self.stx_pnt, dist1))
+            qs2 = SouthTexasCityFt.objects.filter(point__dwithin=(self.stx_pnt, dist2))
+            for qs in qs1, qs2:
+                self.assertEqual(tx_cities, self.get_names(qs))
 
+        # Now performing the `dwithin` queries on a geodetic coordinate system.
         for dist in au_dists:
             if isinstance(dist, D) and not oracle: type_error = True
             else: type_error = False
@@ -70,23 +94,29 @@ class DistanceTest(unittest.TestCase):
                 # Distance objects into a DWithin query using a geodetic field.  
                 self.assertRaises(TypeError, qs.count)
             else:
-                self.assertEqual(au_cities, self.get_cities(qs))
+                self.assertEqual(au_cities, self.get_names(qs))
 
-    def test03_distance_aggregate(self):
-        "Testing the `distance` GeoQuerySet method."
+    def test03a_distance_method(self):
+        "Testing the `distance` GeoQuerySet method on projected coordinate systems."
         # The point for La Grange, TX
         lagrange = GEOSGeometry('POINT(-96.876369 29.905320)', 4326)
-        # Got these from using the raw SQL statement:
-        #  SELECT ST_Distance(point, ST_Transform(ST_GeomFromText('POINT(-96.876369 29.905320)', 4326),32140)) FROM distapp_southtexascity;
-        distances = [147075.069813, 139630.198056, 140888.552826,
-                     138809.684197, 158309.246259, 212183.594374,
-                     70870.188967, 165337.758878, 102128.654360, 
-                     139196.085105]
+        # Reference distances in feet and in meters. Got these values from 
+        # using the provided raw SQL statements.
+        #  SELECT ST_Distance(point, ST_Transform(ST_GeomFromText('POINT(-96.876369 29.905320)', 4326), 32140)) FROM distapp_southtexascity;
+        m_distances = [147075.069813, 139630.198056, 140888.552826,
+                       138809.684197, 158309.246259, 212183.594374,
+                       70870.188967, 165337.758878, 139196.085105]
+        #  SELECT ST_Distance(point, ST_Transform(ST_GeomFromText('POINT(-96.876369 29.905320)', 4326), 2278)) FROM distapp_southtexascityft;
+        ft_distances = [482528.79154625, 458103.408123001, 462231.860397575,
+                        455411.438904354, 519386.252102563, 696139.009211594,
+                        232513.278304279, 542445.630586414, 456679.155883207]
 
-        # Testing when the field name is explicitly set.
-        dist1 = SouthTexasCity.objects.distance('point', lagrange)
+        # Testing using different variations of parameters and using models
+        # with different projected coordinate systems.
+        dist1 = SouthTexasCity.objects.distance(lagrange, field_name='point')
         dist2 = SouthTexasCity.objects.distance(lagrange)  # Using GEOSGeometry parameter
-        dist3 = SouthTexasCity.objects.distance(lagrange.ewkt) # Using EWKT string parameter.
+        dist3 = SouthTexasCityFt.objects.distance(lagrange.ewkt) # Using EWKT string parameter.
+        dist4 = SouthTexasCityFt.objects.distance(lagrange)
 
         # Original query done on PostGIS, have to adjust AlmostEqual tolerance
         # for Oracle.
@@ -94,9 +124,15 @@ class DistanceTest(unittest.TestCase):
         else: tol = 5
 
         # Ensuring expected distances are returned for each distance queryset.
-        for qs in [dist1, dist2, dist3]:
+        for qs in [dist1, dist2, dist3, dist4]:
             for i, c in enumerate(qs):
-                self.assertAlmostEqual(distances[i], c.distance, tol)
+                self.assertAlmostEqual(m_distances[i], c.distance.m, tol)
+                self.assertAlmostEqual(ft_distances[i], c.distance.survey_ft, tol)
+
+    def test03b_distance_method(self):
+        "Testing the `distance` GeoQuerySet method on geodetic coordnate systems."
+        if oracle: tol = 2
+        else: tol = 5
 
         # Now testing geodetic distance aggregation.
         hillsdale = AustraliaCity.objects.get(name='Hillsdale')
@@ -106,61 +142,153 @@ class DistanceTest(unittest.TestCase):
             self.assertRaises(TypeError, AustraliaCity.objects.distance, 'LINESTRING(0 0, 1 1)')
             self.assertRaises(TypeError, AustraliaCity.objects.distance, LineString((0, 0), (1, 1)))
 
-        # Got these distances using the raw SQL statement:
+        # Got the reference distances using the raw SQL statements:
         #  SELECT ST_distance_spheroid(point, ST_GeomFromText('POINT(151.231341 -33.952685)', 4326), 'SPHEROID["WGS 84",6378137.0,298.257223563]') FROM distapp_australiacity WHERE (NOT (id = 11));
-        geodetic_distances = [60504.0628825298, 77023.948962654, 49154.8867507115, 90847.435881812, 217402.811862568, 709599.234619957, 640011.483583758, 7772.00667666425, 1047861.7859506, 1165126.55237647]
+        spheroid_distances = [60504.0628825298, 77023.948962654, 49154.8867507115, 90847.435881812, 217402.811862568, 709599.234619957, 640011.483583758, 7772.00667666425, 1047861.7859506, 1165126.55237647]
+        #  SELECT ST_distance_sphere(point, ST_GeomFromText('POINT(151.231341 -33.952685)', 4326)) FROM distapp_australiacity WHERE (NOT (id = 11));  st_distance_sphere
+        sphere_distances = [60580.7612632291, 77143.7785056615, 49199.2725132184, 90804.4414289463, 217712.63666124, 709131.691061906, 639825.959074112, 7786.80274606706, 1049200.46122281, 1162619.7297006]
 
-        # Ensuring the expected distances are returned.
-        qs = AustraliaCity.objects.exclude(id=hillsdale.id).distance(hillsdale.point)
+        # Testing with spheroid distances first.
+        qs = AustraliaCity.objects.exclude(id=hillsdale.id).distance(hillsdale.point, spheroid=True)
         for i, c in enumerate(qs):
-            self.assertAlmostEqual(geodetic_distances[i], c.distance, tol)
+            self.assertAlmostEqual(spheroid_distances[i], c.distance.m, tol)
+        if postgis:
+            # PostGIS uses sphere-only distances by default, testing these as well.
+            qs =  AustraliaCity.objects.exclude(id=hillsdale.id).distance(hillsdale.point)
+            for i, c in enumerate(qs):
+                self.assertAlmostEqual(sphere_distances[i], c.distance.m, tol)
 
-    def test04_distance_lookups(self):
-        "Testing the `distance_lt`, `distance_gt`, `distance_lte`, and `distance_gte` lookup types."
-        # Only two cities (Houston and Southside Place) should be
-        # within 7km of the given point.
-        dists = [D(km=7), D(mi=4.349), # Distance instances in different units.
-                 7000, 7000.0, Decimal(7000), # int, float, Decimal parameters.
-                 ]
+    @no_oracle # Oracle already handles geographic distance calculation.
+    def test03c_distance_method(self):
+        "Testing the `distance` GeoQuerySet method used with `transform` on a geographic field."
+        # Normally you can't compute distances from a geometry field
+        # that is not a PointField (on PostGIS).
+        self.assertRaises(TypeError, CensusZipcode.objects.distance, self.stx_pnt)
+        
+        # We'll be using a Polygon (created by buffering the centroid
+        # of 77005 to 100m) -- which aren't allowed in geographic distance
+        # queries normally, however our field has been transformed to
+        # a non-geographic system.
+        z = SouthTexasZipcode.objects.get(name='77005')
 
-        for dist in dists:
-            qs = SouthTexasCity.objects.filter(point__dwithin=(self.stx_pnt, dist))
-            for c in qs:
-                cities = self.get_cities(qs)
-                self.assertEqual(cities, ['Downtown Houston', 'Southside Place'])
+        # Reference query:
+        # SELECT ST_Distance(ST_Transform("distapp_censuszipcode"."poly", 32140), ST_GeomFromText('<buffer_wkt>', 32140)) FROM "distapp_censuszipcode";
+        dists_m = [3553.30384972258, 1243.18391525602, 2186.15439472242]
 
-        # Now only retrieving the cities within a 20km 'donut' w/a 7km radius 'hole'
-        # (thus, Houston and Southside place will be excluded)
-        qs = SouthTexasCity.objects.filter(point__distance_gte=(self.stx_pnt, D(km=7))).filter(point__distance_lte=(self.stx_pnt, D(km=20)))
-        cities = self.get_cities(qs)
-        self.assertEqual(cities, ['Bellaire', 'Pearland', 'West University Place'])
+        # Having our buffer in the SRID of the transformation and of the field
+        # -- should get the same results. The first buffer has no need for
+        # transformation SQL because it is the same SRID as what was given
+        # to `transform()`.  The second buffer will need to be transformed,
+        # however.
+        buf1 = z.poly.centroid.buffer(100)
+        buf2 = buf1.transform(4269, clone=True)
+        for buf in [buf1, buf2]:
+            qs = CensusZipcode.objects.exclude(name='77005').transform(32140).distance(buf)
+            self.assertEqual(['77002', '77025', '77401'], self.get_names(qs))
+            for i, z in enumerate(qs):
+                self.assertAlmostEqual(z.distance.m, dists_m[i], 5)
 
-    def test05_geodetic_distance(self):
-        "Testing distance lookups on geodetic coordinate systems."
+    def test04_distance_lookups(self):
+        "Testing the `distance_lt`, `distance_gt`, `distance_lte`, and `distance_gte` lookup types."
+        # Retrieving the cities within a 20km 'donut' w/a 7km radius 'hole'
+        # (thus, Houston and Southside place will be excluded as tested in
+        # the `test02_dwithin` above).
+        qs1 = SouthTexasCity.objects.filter(point__distance_gte=(self.stx_pnt, D(km=7))).filter(point__distance_lte=(self.stx_pnt, D(km=20)))
+        qs2 = SouthTexasCityFt.objects.filter(point__distance_gte=(self.stx_pnt, D(km=7))).filter(point__distance_lte=(self.stx_pnt, D(km=20)))
+        for qs in qs1, qs2:
+            cities = self.get_names(qs)
+            self.assertEqual(cities, ['Bellaire', 'Pearland', 'West University Place'])
+
+        # Doing a distance query using Polygons instead of a Point.
+        z = SouthTexasZipcode.objects.get(name='77005')
+        qs = SouthTexasZipcode.objects.exclude(name='77005').filter(poly__distance_lte=(z.poly, D(m=275)))
+        self.assertEqual(['77025', '77401'], self.get_names(qs))
+        # If we add a little more distance 77002 should be included.
+        qs = SouthTexasZipcode.objects.exclude(name='77005').filter(poly__distance_lte=(z.poly, D(m=300)))
+        self.assertEqual(['77002', '77025', '77401'], self.get_names(qs))
         
+    def test05_geodetic_distance_lookups(self):
+        "Testing distance lookups on geodetic coordinate systems."
         if not oracle:
             # Oracle doesn't have this limitation -- PostGIS only allows geodetic
             # distance queries from Points to PointFields.
             mp = GEOSGeometry('MULTIPOINT(0 0, 5 23)')
             self.assertRaises(TypeError,
                               AustraliaCity.objects.filter(point__distance_lte=(mp, D(km=100))))
-            
-        hobart = AustraliaCity.objects.get(name='Hobart')
-        
+            # Too many params (4 in this case) should raise a ValueError.
+            self.assertRaises(ValueError, 
+                              AustraliaCity.objects.filter(point__distance_lte=('POINT(5 23)', D(km=100), 'spheroid', '4')).count)
+
+        # Not enough params should raise a ValueError.
+        self.assertRaises(ValueError,
+                          AustraliaCity.objects.filter(point__distance_lte=('POINT(5 23)',)).count)
+
         # Getting all cities w/in 550 miles of Hobart.
+        hobart = AustraliaCity.objects.get(name='Hobart')
         qs = AustraliaCity.objects.exclude(name='Hobart').filter(point__distance_lte=(hobart.point, D(mi=550)))
-        cities = self.get_cities(qs)
+        cities = self.get_names(qs)
         self.assertEqual(cities, ['Batemans Bay', 'Canberra', 'Melbourne'])
 
         # Cities that are either really close or really far from Wollongong --
         # and using different units of distance.
         wollongong = AustraliaCity.objects.get(name='Wollongong')
-        gq1 = GeoQ(point__distance_lte=(wollongong.point, D(yd=19500))) # Yards (~17km)
-        gq2 = GeoQ(point__distance_gte=(wollongong.point, D(nm=400)))   # Nautical Miles
-        qs = AustraliaCity.objects.exclude(name='Wollongong').filter(gq1 | gq2)
-        cities = self.get_cities(qs)
-        self.assertEqual(cities, ['Adelaide', 'Hobart', 'Shellharbour', 'Thirroul'])
+        d1, d2 = D(yd=19500), D(nm=400) # Yards (~17km) & Nautical miles.
+
+        # Normal geodetic distance lookup (uses `distance_sphere` on PostGIS.
+        gq1 = GeoQ(point__distance_lte=(wollongong.point, d1))
+        gq2 = GeoQ(point__distance_gte=(wollongong.point, d2))
+        qs1 = AustraliaCity.objects.exclude(name='Wollongong').filter(gq1 | gq2)
+
+        # Geodetic distance lookup but telling GeoDjango to use `distance_spheroid`
+        # instead (we should get the same results b/c accuracy variance won't matter
+        # in this test case). Using `Q` instead of `GeoQ` to be different (post-qsrf
+        # it doesn't matter).
+        if postgis:
+            gq3 = Q(point__distance_lte=(wollongong.point, d1, 'spheroid'))
+            gq4 = Q(point__distance_gte=(wollongong.point, d2, 'spheroid'))
+            qs2 = AustraliaCity.objects.exclude(name='Wollongong').filter(gq3 | gq4)
+            querysets = [qs1, qs2]
+        else:
+            querysets = [qs1]
+
+        for qs in querysets:
+            cities = self.get_names(qs)
+            self.assertEqual(cities, ['Adelaide', 'Hobart', 'Shellharbour', 'Thirroul'])
+
+    def test06_area(self):
+        "Testing the `area` GeoQuerySet method."
+        # Reference queries:
+        # SELECT ST_Area(poly) FROM distapp_southtexaszipcode;
+        area_sq_m = [5437908.90234375, 10183031.4389648, 11254471.0073242, 9881708.91772461]
+        # Tolerance has to be lower for Oracle and differences
+        # with GEOS 3.0.0RC4
+        tol = 2
+        for i, z in enumerate(SouthTexasZipcode.objects.area()):
+            self.assertAlmostEqual(area_sq_m[i], z.area.sq_m, tol)
+
+    def test07_length(self):
+        "Testing the `length` GeoQuerySet method."
+        # Reference query (should use `length_spheroid`).
+        # SELECT ST_length_spheroid(ST_GeomFromText('<wkt>', 4326) 'SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]]');
+        len_m = 473504.769553813
+        qs = Interstate.objects.length()
+        if oracle: tol = 2
+        else: tol = 7
+        self.assertAlmostEqual(len_m, qs[0].length.m, tol)
+
+    def test08_perimeter(self):
+        "Testing the `perimeter` GeoQuerySet method."
+        # Reference query:
+        # SELECT ST_Perimeter(distapp_southtexaszipcode.poly) FROM distapp_southtexaszipcode;
+        perim_m = [18404.3550889361, 15627.2108551001, 20632.5588368978, 17094.5996143697]
+        if oracle: tol = 2
+        else: tol = 7
+        for i, z in enumerate(SouthTexasZipcode.objects.perimeter()):
+            self.assertAlmostEqual(perim_m[i], z.perimeter.m, tol)
 
+        # Running on points; should return 0.
+        for i, c in enumerate(SouthTexasCity.objects.perimeter(model_att='perim')):
+            self.assertEqual(0, c.perim.m)
 
 def suite():
     s = unittest.TestSuite()
diff --git a/django/contrib/gis/tests/geoapp/tests.py b/django/contrib/gis/tests/geoapp/tests.py
index b06ec2130b..e2fd392f3a 100644
--- a/django/contrib/gis/tests/geoapp/tests.py
+++ b/django/contrib/gis/tests/geoapp/tests.py
@@ -28,14 +28,10 @@ class GeoModelTest(unittest.TestCase):
             def get_file(wkt_file):
                 return os.path.join(data_dir, wkt_file)
 
-            co = State(name='Colorado', poly=fromfile(get_file('co.wkt')))
-            co.save()
-            ks = State(name='Kansas', poly=fromfile(get_file('ks.wkt')))
-            ks.save()
-            tx = Country(name='Texas', mpoly=fromfile(get_file('tx.wkt')))
-            tx.save()
-            nz = Country(name='New Zealand', mpoly=fromfile(get_file('nz.wkt')))
-            nz.save()
+            State(name='Colorado', poly=fromfile(get_file('co.wkt'))).save()
+            State(name='Kansas', poly=fromfile(get_file('ks.wkt'))).save()
+            Country(name='Texas', mpoly=fromfile(get_file('tx.wkt'))).save()
+            Country(name='New Zealand', mpoly=fromfile(get_file('nz.wkt'))).save()
 
         # Ensuring that data was loaded from initial SQL.
         self.assertEqual(2, Country.objects.count())
@@ -49,7 +45,7 @@ class GeoModelTest(unittest.TestCase):
     def test02_proxy(self):
         "Testing Lazy-Geometry support (using the GeometryProxy)."
         if DISABLE: return
-        #### Testing on a Point
+        ## Testing on a Point
         pnt = Point(0, 0)
         nullcity = City(name='NullCity', point=pnt)
         nullcity.save()
@@ -86,7 +82,7 @@ class GeoModelTest(unittest.TestCase):
         self.assertEqual(Point(23, 5), City.objects.get(name='NullCity').point)
         nullcity.delete()
 
-        #### Testing on a Polygon
+        ## Testing on a Polygon
         shell = LinearRing((0, 0), (0, 100), (100, 100), (100, 0), (0, 0))
         inner = LinearRing((40, 40), (40, 60), (60, 60), (60, 40), (40, 40))
 
@@ -136,7 +132,7 @@ class GeoModelTest(unittest.TestCase):
             ref_kml = ref_kml2
 
         # Ensuring the KML is as expected.
-        ptown1 = City.objects.kml('point', precision=9).get(name='Pueblo')
+        ptown1 = City.objects.kml(field_name='point', precision=9).get(name='Pueblo')
         ptown2 = City.objects.kml(precision=9).get(name='Pueblo')
         for ptown in [ptown1, ptown2]:
             self.assertEqual(ref_kml, ptown.kml)
@@ -147,8 +143,8 @@ class GeoModelTest(unittest.TestCase):
         # Should throw a TypeError when tyring to obtain GML from a
         #  non-geometry field.
         qs = City.objects.all()
-        self.assertRaises(TypeError, qs.gml, 'name')
-        ptown1 = City.objects.gml('point', precision=9).get(name='Pueblo')
+        self.assertRaises(TypeError, qs.gml, field_name='name')
+        ptown1 = City.objects.gml(field_name='point', precision=9).get(name='Pueblo')
         ptown2 = City.objects.gml(precision=9).get(name='Pueblo')
 
         if oracle:
@@ -172,12 +168,12 @@ class GeoModelTest(unittest.TestCase):
         # Asserting the result of the transform operation with the values in
         #  the pre-transformed points.  Oracle does not have the 3084 SRID.
         if not oracle:
-            h = City.objects.transform('point', srid=htown.srid).get(name='Houston')
+            h = City.objects.transform(htown.srid).get(name='Houston')
             self.assertEqual(3084, h.point.srid)
             self.assertAlmostEqual(htown.x, h.point.x, prec)
             self.assertAlmostEqual(htown.y, h.point.y, prec)
 
-        p1 = City.objects.transform('point', srid=ptown.srid).get(name='Pueblo')
+        p1 = City.objects.transform(ptown.srid, field_name='point').get(name='Pueblo')
         p2 = City.objects.transform(srid=ptown.srid).get(name='Pueblo')
         for p in [p1, p2]:
             self.assertEqual(2774, p.point.srid)
@@ -186,7 +182,7 @@ class GeoModelTest(unittest.TestCase):
 
     @no_oracle # Most likely can do this in Oracle, however, it is not yet implemented (patches welcome!)
     def test05_extent(self):
-        "Testing the extent() GeoManager method."
+        "Testing the `extent` GeoQuerySet method."
         if DISABLE: return
         # Reference query:
         # `SELECT ST_extent(point) FROM geoapp_city WHERE (name='Houston' or name='Dallas');`
@@ -199,6 +195,17 @@ class GeoModelTest(unittest.TestCase):
         for val, exp in zip(extent, expected):
             self.assertAlmostEqual(exp, val, 8)
 
+    @no_oracle
+    def test06_make_line(self):
+        "Testing the `make_line` GeoQuerySet method."
+        # Ensuring that a `TypeError` is raised on models without PointFields.
+        self.assertRaises(TypeError, State.objects.make_line)
+        self.assertRaises(TypeError, Country.objects.make_line)
+        # Reference query:
+        # SELECT AsText(ST_MakeLine(geoapp_city.point)) FROM geoapp_city;
+        self.assertEqual(GEOSGeometry('LINESTRING(-95.363151 29.763374,-96.801611 32.782057,-97.521157 34.464642,174.783117 -41.315268,-104.609252 38.255001,-95.23506 38.971823,-87.650175 41.850385,-123.305196 48.462611)', srid=4326),
+                         City.objects.make_line())
+
     def test09_disjoint(self):
         "Testing the `disjoint` lookup type."
         if DISABLE: return
@@ -317,8 +324,7 @@ class GeoModelTest(unittest.TestCase):
         # Saving another commonwealth w/a NULL geometry.
         if not oracle:
             # TODO: Fix saving w/NULL geometry on Oracle.
-            nmi = State(name='Northern Mariana Islands', poly=None)
-            nmi.save()
+            State(name='Northern Mariana Islands', poly=None).save()
 
     @no_oracle # No specific `left` or `right` operators in Oracle.
     def test13_left_right(self):
@@ -416,34 +422,36 @@ class GeoModelTest(unittest.TestCase):
         c = City()
         self.assertEqual(c.point, None)
 
-    def test17_union(self):
-        "Testing the union() GeoManager method."
+    def test17_unionagg(self):
+        "Testing the `unionagg` (aggregate union) GeoManager method."
         if DISABLE: return
         tx = Country.objects.get(name='Texas').mpoly
-        # Houston, Dallas, San Antonio
-        union = fromstr('MULTIPOINT(-98.493183 29.424170,-96.801611 32.782057,-95.363151 29.763374)')
+        # Houston, Dallas, San Antonio -- Oracle has different order.
+        union1 = fromstr('MULTIPOINT(-98.493183 29.424170,-96.801611 32.782057,-95.363151 29.763374)')
+        union2 = fromstr('MULTIPOINT(-96.801611 32.782057,-95.363151 29.763374,-98.493183 29.424170)')
         qs = City.objects.filter(point__within=tx)
-        self.assertRaises(TypeError, qs.union, 'name')
-        u1 = qs.union('point')
-        u2 = qs.union()
-        self.assertEqual(True, union.equals_exact(u1, 10)) # Going up to 10 digits of precision.
-        self.assertEqual(True, union.equals_exact(u2, 10))
+        self.assertRaises(TypeError, qs.unionagg, 'name')
+        u1 = qs.unionagg(field_name='point')
+        u2 = qs.unionagg()
+        tol = 0.00001
+        if SpatialBackend.oracle:
+            union = union2
+        else:
+            union = union1
+        self.assertEqual(True, union.equals_exact(u1, tol))
+        self.assertEqual(True, union.equals_exact(u2, tol))
         qs = City.objects.filter(name='NotACity')
-        self.assertEqual(None, qs.union('point'))
+        self.assertEqual(None, qs.unionagg(field_name='point'))
 
     def test18_geometryfield(self):
         "Testing GeometryField."
         if DISABLE: return
-        f1 = Feature(name='Point', geom=Point(1, 1))
-        f2 = Feature(name='LineString', geom=LineString((0, 0), (1, 1), (5, 5)))
-        f3 = Feature(name='Polygon', geom=Polygon(LinearRing((0, 0), (0, 5), (5, 5), (5, 0), (0, 0))))
-        f4 = Feature(name='GeometryCollection', 
-                     geom=GeometryCollection(Point(2, 2), LineString((0, 0), (2, 2)), 
-                                             Polygon(LinearRing((0, 0), (0, 5), (5, 5), (5, 0), (0, 0)))))
-        f1.save()
-        f2.save()
-        f3.save()
-        f4.save()
+        Feature(name='Point', geom=Point(1, 1)).save()
+        Feature(name='LineString', geom=LineString((0, 0), (1, 1), (5, 5))).save()
+        Feature(name='Polygon', geom=Polygon(LinearRing((0, 0), (0, 5), (5, 5), (5, 0), (0, 0)))).save()
+        Feature(name='GeometryCollection', 
+                geom=GeometryCollection(Point(2, 2), LineString((0, 0), (2, 2)), 
+                                        Polygon(LinearRing((0, 0), (0, 5), (5, 5), (5, 0), (0, 0))))).save()
 
         f_1 = Feature.objects.get(name='Point')
         self.assertEqual(True, isinstance(f_1.geom, Point))
@@ -458,6 +466,82 @@ class GeoModelTest(unittest.TestCase):
         self.assertEqual(True, isinstance(f_4.geom, GeometryCollection))
         self.assertEqual(f_3.geom, f_4.geom[2])
     
+    def test19_centroid(self):
+        "Testing the `centroid` GeoQuerySet method."
+        qs = State.objects.exclude(poly__isnull=True).centroid()
+        if oracle: tol = 0.1
+        else: tol = 0.000000001
+        for s in qs:
+            self.assertEqual(True, s.poly.centroid.equals_exact(s.centroid, tol))
+
+    def test20_pointonsurface(self):
+        "Testing the `point_on_surface` GeoQuerySet method."
+        # Reference values.
+        if SpatialBackend.oracle:
+            # SELECT SDO_UTIL.TO_WKTGEOMETRY(SDO_GEOM.SDO_POINTONSURFACE(GEOAPP_COUNTRY.MPOLY, 0.05)) FROM GEOAPP_COUNTRY;
+            ref = {'New Zealand' : fromstr('POINT (174.616364 -36.100861)', srid=4326),
+                   'Texas' : fromstr('POINT (-103.002434 36.500397)', srid=4326),
+                   }
+        elif SpatialBackend.postgis:
+            # Using GEOSGeometry to compute the reference point on surface values 
+            # -- since PostGIS also uses GEOS these should be the same.
+            ref = {'New Zealand' : Country.objects.get(name='New Zealand').mpoly.point_on_surface,
+                   'Texas' : Country.objects.get(name='Texas').mpoly.point_on_surface
+                   }
+        for cntry in Country.objects.point_on_surface():
+            self.assertEqual(ref[cntry.name], cntry.point_on_surface)
+
+    @no_oracle
+    def test21_scale(self):
+        "Testing the `scale` GeoQuerySet method."
+        xfac, yfac = 2, 3
+        qs = Country.objects.scale(xfac, yfac, model_att='scaled')
+        for c in qs:
+            for p1, p2 in zip(c.mpoly, c.scaled):
+                for r1, r2 in zip(p1, p2):
+                    for c1, c2 in zip(r1.coords, r2.coords):
+                        self.assertEqual(c1[0] * xfac, c2[0])
+                        self.assertEqual(c1[1] * yfac, c2[1])
+
+    @no_oracle
+    def test22_translate(self):
+        "Testing the `translate` GeoQuerySet method."
+        xfac, yfac = 5, -23
+        qs = Country.objects.translate(xfac, yfac, model_att='translated')
+        for c in qs:
+            for p1, p2 in zip(c.mpoly, c.translated):
+                for r1, r2 in zip(p1, p2):
+                    for c1, c2 in zip(r1.coords, r2.coords):
+                        self.assertEqual(c1[0] + xfac, c2[0])
+                        self.assertEqual(c1[1] + yfac, c2[1])
+
+    def test23_numgeom(self):
+        "Testing the `num_geom` GeoQuerySet method."
+        # Both 'countries' only have two geometries.
+        for c in Country.objects.num_geom(): self.assertEqual(2, c.num_geom)
+        for c in City.objects.filter(point__isnull=False).num_geom(): 
+            # Oracle will return 1 for the number of geometries on non-collections,
+            # whereas PostGIS will return None.
+            if postgis: self.assertEqual(None, c.num_geom)
+            else: self.assertEqual(1, c.num_geom)
+
+    def test24_numpoints(self):
+        "Testing the `num_points` GeoQuerySet method."
+        for c in Country.objects.num_points(): self.assertEqual(c.mpoly.num_points, c.num_points)
+        if postgis:
+            # Oracle cannot count vertices in Point geometries.
+            for c in City.objects.num_points(): self.assertEqual(1, c.num_points)
+
+    @no_oracle
+    def test25_geoset(self):
+        "Testing the `difference`, `intersection`, `sym_difference`, and `union` GeoQuerySet methods."
+        geom = Point(5, 23)
+        for c in Country.objects.all().intersection(geom).difference(geom).sym_difference(geom).union(geom):
+            self.assertEqual(c.mpoly.difference(geom), c.difference)
+            self.assertEqual(c.mpoly.intersection(geom), c.intersection)
+            self.assertEqual(c.mpoly.sym_difference(geom), c.sym_difference)
+            self.assertEqual(c.mpoly.union(geom), c.union)
+
 def suite():
     s = unittest.TestSuite()
     s.addTest(unittest.makeSuite(GeoModelTest))
diff --git a/django/contrib/gis/tests/geoapp/tests_mysql.py b/django/contrib/gis/tests/geoapp/tests_mysql.py
index 89496e81b9..4e7c411f52 100644
--- a/django/contrib/gis/tests/geoapp/tests_mysql.py
+++ b/django/contrib/gis/tests/geoapp/tests_mysql.py
@@ -169,9 +169,9 @@ class GeoModelTest(unittest.TestCase):
     
     def test07_mysql_limitations(self):
         "Testing that union(), kml(), gml() raise exceptions."
-        self.assertRaises(ImproperlyConfigured, City.objects.union, 'point')
-        self.assertRaises(ImproperlyConfigured, State.objects.all().kml, 'poly')
-        self.assertRaises(ImproperlyConfigured, Country.objects.all().gml, 'mpoly')
+        self.assertRaises(ImproperlyConfigured, City.objects.union, Point(5, 23), field_name='point')
+        self.assertRaises(ImproperlyConfigured, State.objects.all().kml, field_name='poly')
+        self.assertRaises(ImproperlyConfigured, Country.objects.all().gml, field_name='mpoly')
 
 def suite():
     s = unittest.TestSuite()
diff --git a/django/contrib/gis/tests/layermap/models.py b/django/contrib/gis/tests/layermap/models.py
index fe7604f980..5dbd528030 100644
--- a/django/contrib/gis/tests/layermap/models.py
+++ b/django/contrib/gis/tests/layermap/models.py
@@ -19,7 +19,7 @@ class City(models.Model):
     name = models.CharField(max_length=25)
     population = models.IntegerField()
     density = models.DecimalField(max_digits=7, decimal_places=1)
-    date = models.DateField()
+    dt = models.DateField()
     point = models.PointField()
     objects = models.GeoManager()
 
@@ -42,7 +42,7 @@ cofeat_mapping = {'name' : 'Name',
 city_mapping = {'name' : 'Name',
                 'population' : 'Population',
                 'density' : 'Density',
-                'date' : 'Created',
+                'dt' : 'Created',
                 'point' : 'POINT',
                 }
 
diff --git a/django/contrib/gis/tests/layermap/tests.py b/django/contrib/gis/tests/layermap/tests.py
index 278c1a2998..740ab8647e 100644
--- a/django/contrib/gis/tests/layermap/tests.py
+++ b/django/contrib/gis/tests/layermap/tests.py
@@ -69,7 +69,7 @@ class LayerMapTest(unittest.TestCase):
             city = City.objects.get(name=feat['Name'].value)
             self.assertEqual(feat['Population'].value, city.population)
             self.assertEqual(Decimal(str(feat['Density'])), city.density)
-            self.assertEqual(feat['Created'].value, city.date)
+            self.assertEqual(feat['Created'].value, city.dt)
 
             # Comparing the geometries.
             pnt1, pnt2 = feat.geom, city.point
diff --git a/django/contrib/gis/tests/relatedapp/tests.py b/django/contrib/gis/tests/relatedapp/tests.py
index a49b66c0dd..5fe63cbc8e 100644
--- a/django/contrib/gis/tests/relatedapp/tests.py
+++ b/django/contrib/gis/tests/relatedapp/tests.py
@@ -34,7 +34,7 @@ class RelatedGeoModelTest(unittest.TestCase):
         
     @no_mysql
     def test03_transform_related(self):
-        "Testing the `transform` GeoManager method on related geographic models."
+        "Testing the `transform` GeoQuerySet method on related geographic models."
         # All the transformations are to state plane coordinate systems using
         # US Survey Feet (thus a tolerance of 0 implies error w/in 1 survey foot).
         if postgis:
@@ -47,6 +47,7 @@ class RelatedGeoModelTest(unittest.TestCase):
         def check_pnt(ref, pnt):
             self.assertAlmostEqual(ref.x, pnt.x, tol)
             self.assertAlmostEqual(ref.y, pnt.y, tol)
+            self.assertEqual(ref.srid, pnt.srid)
 
         # Turning on debug so we can manually verify the number of SQL queries issued.
         # DISABLED: the number of queries count testing mechanism is way too brittle.
@@ -62,13 +63,35 @@ class RelatedGeoModelTest(unittest.TestCase):
 
         for name, srid, wkt in transformed:
             # Doing this implicitly sets `select_related` select the location.
-            qs = list(City.objects.filter(name=name).transform('location__point', srid))
-            check_pnt(GEOSGeometry(wkt), qs[0].location.point) 
+            qs = list(City.objects.filter(name=name).transform(srid, field_name='location__point'))
+            check_pnt(GEOSGeometry(wkt, srid), qs[0].location.point) 
         #settings.DEBUG= dbg
 
         # Verifying the number of issued SQL queries.
         #self.assertEqual(nqueries, len(connection.queries))
 
+    @no_mysql
+    def test04_related_aggregate(self):
+        "Testing the `extent` and `unionagg` GeoQuerySet aggregates on related geographic models."
+        if postgis:
+            # One for all locations, one that excludes Roswell.
+            all_extent = (-104.528060913086, 33.0583305358887,-79.4607315063477, 40.1847610473633)
+            txpa_extent = (-97.51611328125, 33.0583305358887,-79.4607315063477, 40.1847610473633)
+            e1 = City.objects.extent(field_name='location__point')
+            e2 = City.objects.exclude(name='Roswell').extent(field_name='location__point')
+            for ref, e in [(all_extent, e1), (txpa_extent, e2)]:
+                for ref_val, e_val in zip(ref, e): self.assertAlmostEqual(ref_val, e_val)
+
+        # The second union is for a query that has something in the WHERE clause.
+        ref_u1 = GEOSGeometry('MULTIPOINT(-104.528056 33.387222,-97.516111 33.058333,-79.460734 40.18476)', 4326)
+        ref_u2 = GEOSGeometry('MULTIPOINT(-97.516111 33.058333,-79.460734 40.18476)', 4326)
+        u1 = City.objects.unionagg(field_name='location__point')
+        u2 = City.objects.exclude(name='Roswell').unionagg(field_name='location__point')
+        self.assertEqual(ref_u1, u1)
+        self.assertEqual(ref_u2, u2)
+
+    # TODO: Related tests for KML, GML, and distance lookups.
+        
 def suite():
     s = unittest.TestSuite()
     s.addTest(unittest.makeSuite(RelatedGeoModelTest))