diff --git a/docs/guide/defining-documents.rst b/docs/guide/defining-documents.rst
index de0e7272..e333674e 100644
--- a/docs/guide/defining-documents.rst
+++ b/docs/guide/defining-documents.rst
@@ -134,8 +134,8 @@ document class as the first argument::
     class Page(Document):
         comments = ListField(EmbeddedDocumentField(Comment))
 
-    comment1 = Comment('Good work!')
-    comment2 = Comment('Nice article!')
+    comment1 = Comment(content='Good work!')
+    comment2 = Comment(content='Nice article!')
     page = Page(comments=[comment1, comment2])
 
 Dictionary Fields
diff --git a/mongoengine/base.py b/mongoengine/base.py
index ae9e1eb3..b7f7ce87 100644
--- a/mongoengine/base.py
+++ b/mongoengine/base.py
@@ -508,6 +508,17 @@ class BaseDocument(object):
                 return True
         return False
 
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __hash__(self):
+        """ For list, dic key  """
+        if self.pk is None:
+            # For new object
+            return super(BaseDocument,self).__hash__()
+        else:
+            return hash(self.pk)
+
 if sys.version_info < (2, 5):
     # Prior to Python 2.5, Exception was an old-style class
     import types
diff --git a/mongoengine/document.py b/mongoengine/document.py
index e64092e8..196662c3 100644
--- a/mongoengine/document.py
+++ b/mongoengine/document.py
@@ -67,7 +67,7 @@ class Document(BaseDocument):
         :param safe: check if the operation succeeded before returning
         :param force_insert: only try to create a new document, don't allow 
             updates of existing documents
-        :param validate: validates the document; set to ``False`` for skiping
+        :param validate: validates the document; set to ``False`` to skip.
         """
         if validate:
             self.validate()
diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index 3d78e9e3..c06fdd4d 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -663,9 +663,6 @@ class GridFSProxy(object):
     def close(self):
         if self.newfile:
             self.newfile.close()
-        else:
-            msg = "The close() method is only necessary after calling write()"
-            warnings.warn(msg)
 
 
 class FileField(BaseField):
diff --git a/tests/document.py b/tests/document.py
index 67c21a46..0da7b93e 100644
--- a/tests/document.py
+++ b/tests/document.py
@@ -729,6 +729,54 @@ class DocumentTest(unittest.TestCase):
     def tearDown(self):
         self.Person.drop_collection()
 
+    def test_document_hash(self):
+        """Test document in list, dict, set
+        """
+        class User(Document):
+            pass
+
+        class BlogPost(Document):
+            pass
+        
+        # Clear old datas
+        User.drop_collection()
+        BlogPost.drop_collection()
+
+        u1 = User.objects.create()
+        u2 = User.objects.create()
+        u3 = User.objects.create()
+        u4 = User() # New object
+
+        b1 = BlogPost.objects.create()
+        b2 = BlogPost.objects.create()
+
+        # in List
+        all_user_list = list(User.objects.all())
+
+        self.assertTrue(u1 in all_user_list)
+        self.assertTrue(u2 in all_user_list)
+        self.assertTrue(u3 in all_user_list)
+        self.assertFalse(u4 in all_user_list) # New object
+        self.assertFalse(b1 in all_user_list) # Other object
+        self.assertFalse(b2 in all_user_list) # Other object
+
+        # in Dict
+        all_user_dic = {}
+        for u in User.objects.all():
+            all_user_dic[u] = "OK"
+
+        self.assertEqual(all_user_dic.get(u1, False), "OK" )
+        self.assertEqual(all_user_dic.get(u2, False), "OK" )
+        self.assertEqual(all_user_dic.get(u3, False), "OK" )
+        self.assertEqual(all_user_dic.get(u4, False), False ) # New object
+        self.assertEqual(all_user_dic.get(b1, False), False ) # Other object
+        self.assertEqual(all_user_dic.get(b2, False), False ) # Other object
+
+        # in Set
+        all_user_set = set(User.objects.all())
+        
+        self.assertTrue(u1 in all_user_set )
+        
 
 if __name__ == '__main__':
     unittest.main()