diff --git a/django/db/models/base.py b/django/db/models/base.py
index 79a1233df7..b3a4ab361f 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -34,12 +34,11 @@ class ModelBase(type):
 
         model_module = sys.modules[new_class.__module__]
 
-        # Figure out the app_label by looking one level up.
-        # For 'django.contrib.sites.models', this would be 'sites'.
-        app_label = model_module.__name__.split('.')[-2]
-
-        # Cache the app label.
-        new_class._meta.app_label = app_label
+        if not hasattr(new_class._meta, 'app_label') or \
+                new_class._meta.app_label is None:
+            # Figure out the app_label by looking one level up.
+            # For 'django.contrib.sites.models', this would be 'sites'.
+            new_class._meta.app_label = model_module.__name__.split('.')[-2]
 
         # Add all attributes to the class.
         for obj_name, obj in attrs.items():
diff --git a/django/db/models/loading.py b/django/db/models/loading.py
index ba33024a31..2464a632a6 100644
--- a/django/db/models/loading.py
+++ b/django/db/models/loading.py
@@ -3,7 +3,7 @@
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 
-__all__ = ('get_apps', 'get_app', 'get_models', 'get_model')
+__all__ = ('get_apps', 'get_app', 'get_models', 'get_model', 'register_models')
 
 _app_list = None # Cache of installed apps.
 
@@ -50,3 +50,14 @@ def get_model(app_label, model_name):
             if model._meta.object_name.lower() == model_name and \
                     model._meta.app_label == app_label:
                 return model
+
+def register_models(app_mod, *models):
+    """
+    Use this from an app's models.py module to register imported Model classes
+    as belonging to the app. e.g.:
+    
+    register_models(sys.modules[__name__], Article, Reporter)
+    """
+    if not hasattr(app_mod, '_MODELS'):
+        app_mod._MODELS = []
+    app_mod._MODELS.extend(models)
diff --git a/django/db/models/options.py b/django/db/models/options.py
index 1c0779ec81..c9ccd293f7 100644
--- a/django/db/models/options.py
+++ b/django/db/models/options.py
@@ -10,7 +10,8 @@ import re
 get_verbose_name = lambda class_name: re.sub('([A-Z])', ' \\1', class_name).lower().strip()
 
 DEFAULT_NAMES = ('verbose_name', 'verbose_name_plural', 'db_table', 'ordering',
-                 'unique_together', 'permissions', 'get_latest_by', 'order_with_respect_to')
+                 'unique_together', 'permissions', 'get_latest_by', 
+                 'order_with_respect_to', 'app_label')
 
 class Options:
     def __init__(self, meta):