diff --git a/django/contrib/gis/db/models/fields/__init__.py b/django/contrib/gis/db/models/fields/__init__.py
index 7b4423bdc1..e2aedbcdb3 100644
--- a/django/contrib/gis/db/models/fields/__init__.py
+++ b/django/contrib/gis/db/models/fields/__init__.py
@@ -1,12 +1,9 @@
-from django.db import models
+# The Django base Field class.
 from django.db.models.fields import Field
-#from GeoTypes import Point
+from django.contrib.gis.db.models.postgis import POSTGIS_TERMS
 
-# Creates the SQL to add the model to the database.  Defaults to using an
-# SRID of 4326 (WGS84 Datum -- 'normal' lat/lon coordinates)
+# Creates the SQL to add the model to the database. 
 def _add_geom(geom, srid, style, model, field, dim=2):
-    from django.db import backend
-
     # Constructing the AddGeometryColumn(...) command -- the style
     # object is passed in from the management module and is used
     # to syntax highlight the command for 'sqlall'
@@ -15,16 +12,38 @@ def _add_geom(geom, srid, style, model, field, dim=2):
           style.SQL_TABLE(model) + "', '" + \
           style.SQL_FIELD(field) + "', " + \
           style.SQL_FIELD(str(srid)) + ", '" + \
-          style.SQL_KEYWORD(geom) + "', " + \
+          style.SQL_COLTYPE(geom) + "', " + \
           style.SQL_KEYWORD(str(dim)) + \
           ');'
     return sql
 
+# Creates an index for the given geometry.
+def _geom_index(geom, style, model, field,
+                index_type='GIST',
+                index_opts='GIST_GEOMETRY_OPTS'):
+    sql = style.SQL_KEYWORD('CREATE INDEX ') + \
+          style.SQL_FIELD(field + '_idx') + \
+          style.SQL_KEYWORD(' ON ') + \
+          style.SQL_TABLE(model) + \
+          style.SQL_KEYWORD(' USING ') + \
+          style.SQL_COLTYPE(index_type) + ' ( ' + \
+          style.SQL_FIELD(field) + ' ' + \
+          style.SQL_KEYWORD(index_opts) + ' );'
+    return sql
+
 class GeometryField(Field):
-    """The base GIS field -- maps to an OpenGIS Geometry type."""
-    
+    "The base GIS field -- maps to the OpenGIS Geometry type."
+
+    # The OpenGIS Geometry name.
     _geom = 'GEOMETRY'
-    _srid = 4326
+
+    def __init__(self, srid=4326, index=False, **kwargs):
+        # Calling the Field initialization function first
+        super(GeometryField, self).__init__(**kwargs)
+
+        # The SRID for the geometry, defaults to 4326
+        self._srid = srid
+        self._index = index
 
     def get_internal_type(self):
         return "NoField"
@@ -32,44 +51,43 @@ class GeometryField(Field):
     def _post_create_sql(self, *args, **kwargs):
         """Returns SQL that will be executed after the model has been created.  Geometry
         columns must be added after creation with the PostGIS AddGeometryColumn() function."""
-        return _add_geom(self._geom, self._srid, *args, **kwargs)
+        post_sql = _add_geom(self._geom, self._srid, *args, **kwargs)
+        if self._index:
+            # Creating geometry indices doesn't yet work.
+            #return '%s\n%s' % (post_sql, _geom_index(self._geom, *args, **kwargs))
+            return post_sql
+        else:
+            return post_sql
 
     def get_db_prep_lookup(self, lookup_type, value):
-        "Returns field's value prepared for database lookup."
-        if lookup_type in ('exact', 'gt', 'gte', 'lt', 'lte', 'month', 'day', 'search', 'overlaps'):
-            return [value]
-        elif lookup_type in ('range', 'in'):
-            return value
-        elif lookup_type in ('contains', 'icontains'):
-            return ["%%%s%%" % prep_for_like_query(value)]
-        elif lookup_type == 'iexact':
-            return [prep_for_like_query(value)]
-        elif lookup_type in ('startswith', 'istartswith'):
-            return ["%s%%" % prep_for_like_query(value)]
-        elif lookup_type in ('endswith', 'iendswith'):
-            return ["%%%s" % prep_for_like_query(value)]
-        elif lookup_type == 'isnull':
-            return []
-        elif lookup_type == 'year':
-            try:
-                value = int(value)
-            except ValueError:
-                raise ValueError("The __year lookup type requires an integer argument")
-            return ['%s-01-01 00:00:00' % value, '%s-12-31 23:59:59.999999' % value]
+        """Returns field's value prepared for database lookup; the SRID of the geometry is
+        included by default in these queries."""
+        if lookup_type in POSTGIS_TERMS:
+            return ['SRID=%d;%s' % (self._srid, value)]
         raise TypeError("Field has invalid lookup: %s" % lookup_type)
 
     def get_db_prep_save(self, value):
+        "Making sure the SRID is included before saving."
         return 'SRID=%d;%s' % (self._srid, value)
     
-
+# The OpenGIS Geometry Type Fields
 class PointField(GeometryField):
     _geom = 'POINT'
 
+class LineString(GeometryField):
+    _geom = 'LINESTRING'
+
 class PolygonField(GeometryField):
     _geom = 'POLYGON'
 
+class MultiPointField(GeometryField):
+    _geom = 'MULTIPOINT'
+
+class MultiLineStringField(GeometryField):
+    _geom = 'MULTILINESTRING'
+
 class MultiPolygonField(GeometryField):
     _geom = 'MULTIPOLYGON'
 
-class GeometryManager(models.Manager):
-    pass
+class GeometryCollectionField(GeometryField):
+    _geom = 'GEOMETRYCOLLECTION'