diff --git a/flask/helpers.py b/flask/helpers.py
index 52b0cebc..5ee38ac0 100644
--- a/flask/helpers.py
+++ b/flask/helpers.py
@@ -117,9 +117,31 @@ def jsonify(*args, **kwargs):
     information about this, have a look at :ref:`json-security`.
 
     .. versionadded:: 0.2
+
+    .. versionadded:: 0.9
+        If the ``padded`` argument is true, the JSON object will be padded
+        for JSONP calls and the response mimetype will be changed to 
+        ``application/javascript``. By default, the request arguments ``callback``
+        and ``jsonp`` will be used as the name for the callback function.
+        This will work with jQuery and most other JavaScript libraries
+        by default.
+
+        If the ``padded`` argument is a string, jsonify will look for
+        the request argument with the same name and use that value as the
+        callback-function name.
     """
     if __debug__:
         _assert_have_json()
+    if 'padded' in kwargs:
+        if isinstance(kwargs['padded'], str):
+            callback = request.args.get(kwargs['padded']) or 'jsonp'
+        else:
+            callback = request.args.get('callback') or \
+                       request.args.get('jsonp') or 'jsonp'
+        del kwargs['padded']
+        json_str = json.dumps(dict(*args, **kwargs), indent=None)
+        content = str(callback) + "(" + json_str + ")"
+        return current_app.response_class(content, mimetype='application/javascript')
     return current_app.response_class(json.dumps(dict(*args, **kwargs),
         indent=None if request.is_xhr else 2), mimetype='application/json')
 
diff --git a/flask/testsuite/helpers.py b/flask/testsuite/helpers.py
index b4dd00ea..1def2770 100644
--- a/flask/testsuite/helpers.py
+++ b/flask/testsuite/helpers.py
@@ -61,11 +61,25 @@ class JSONTestCase(FlaskTestCase):
         @app.route('/dict')
         def return_dict():
             return flask.jsonify(d)
+        @app.route("/padded")
+        def return_padded_json():
+            return flask.jsonify(d, padded=True)
+        @app.route("/padded_custom")
+        def return_padded_json_custom_callback():
+            return flask.jsonify(d, padded='my_func_name')
         c = app.test_client()
         for url in '/kw', '/dict':
             rv = c.get(url)
             self.assert_equal(rv.mimetype, 'application/json')
             self.assert_equal(flask.json.loads(rv.data), d)
+        for get_arg in 'callback=funcName', 'jsonp=funcName':
+            rv = c.get('/padded?' + get_arg)
+            self.assert_( rv.data.startswith("funcName(") )
+            self.assert_( rv.data.endswith(")") )
+            rv_json = rv.data.split('(')[1].split(')')[0]
+            self.assert_equal(flask.json.loads(rv_json), d)
+        rv = c.get('/padded_custom?my_func_name=funcName')
+        self.assert_( rv.data.startswith("funcName(") )
 
     def test_json_attr(self):
         app = flask.Flask(__name__)