Index: runtests.py
===================================================================
--- runtests.py (revision 3668)
+++ runtests.py (working copy)
@@ -120,5 +120,13 @@
     options, args = parser.parse_args()
     if options.settings:
         os.environ['DJANGO_SETTINGS_MODULE'] = options.settings
-        
+    elif not os.environ.has_key('DJANGO_SETTINGS_MODULE'): 
+        try: 
+            import settings 
+            os.environ['DJANGO_SETTINGS_MODULE'] = 'settings' 
+        except ImportError: 
+            parser.print_help()         
+            print "\nERROR: No settings file found. Please use --settings=some_setting_file" 
+            sys.exit(-1)
+    
     django_tests(int(options.verbosity), args)