diff --git a/apiclient/http.py b/apiclient/http.py
index 2481c23..5f4be00 100644
--- a/apiclient/http.py
+++ b/apiclient/http.py
@@ -218,6 +218,7 @@
   'echo_request_headers_as_json' means return the request headers in
      the response body
   'echo_request_body' means return the request body in the response body
+  'echo_request_uri' means return the request uri in the response body
   """
 
   def __init__(self, iterable):
@@ -240,6 +241,8 @@
       content = simplejson.dumps(headers)
     elif content == 'echo_request_body':
       content = body
+    elif content == 'echo_request_uri':
+      content = uri
     return httplib2.Response(resp), content
 
 
diff --git a/apiclient/oauth.py b/apiclient/oauth.py
index 430d068..18877b0 100644
--- a/apiclient/oauth.py
+++ b/apiclient/oauth.py
@@ -170,7 +170,8 @@
     self.store = None
 
   def authorize(self, http):
-    """
+    """Authorize an httplib2.Http instance with these Credentials
+
     Args:
        http - An instance of httplib2.Http
            or something that acts like it.
@@ -213,6 +214,7 @@
           headers['user-agent'] = self.user_agent + ' ' + headers['user-agent']
         else:
           headers['user-agent'] = self.user_agent
+
         resp, content = request_orig(uri, method, body, headers,
                             redirections, connection_type)
         response_code = resp.status
@@ -233,6 +235,149 @@
     return http
 
 
+class TwoLeggedOAuthCredentials(Credentials):
+  """Two Legged Credentials object for OAuth 1.0a.
+
+  The Two Legged object is created directly, not from a flow.  Once you
+  authorize and httplib2.Http instance you can change the requestor and that
+  change will propogate to the authorized httplib2.Http instance. For example:
+
+    http = httplib2.Http()
+    http = credentials.authorize(http)
+
+    credentials.requestor = 'foo@example.info'
+    http.request(...)
+    credentials.requestor = 'bar@example.info'
+    http.request(...)
+  """
+
+  def __init__(self, consumer_key, consumer_secret, user_agent):
+    """
+    Args:
+      consumer_key: string, An OAuth 1.0 consumer key
+      consumer_secret: string, An OAuth 1.0 consumer secret
+      user_agent: string, The HTTP User-Agent to provide for this application.
+    """
+    self.consumer = oauth.Consumer(consumer_key, consumer_secret)
+    self.user_agent = user_agent
+    self.store = None
+
+    # email address of the user to act on the behalf of.
+    self._requestor = None
+
+  @property
+  def invalid(self):
+    """True if the credentials are invalid, such as being revoked.
+
+    Always returns False for Two Legged Credentials.
+    """
+    return False
+
+  def getrequestor(self):
+    return self._requestor
+
+  def setrequestor(self, email):
+    self._requestor = email
+
+  requestor = property(getrequestor, setrequestor, None,
+      'The email address of the user to act on behalf of')
+
+  def set_store(self, store):
+    """Set the storage for the credential.
+
+    Args:
+      store: callable, a callable that when passed a Credential
+        will store the credential back to where it came from.
+        This is needed to store the latest access_token if it
+        has been revoked.
+    """
+    self.store = store
+
+  def __getstate__(self):
+    """Trim the state down to something that can be pickled."""
+    d = copy.copy(self.__dict__)
+    del d['store']
+    return d
+
+  def __setstate__(self, state):
+    """Reconstitute the state of the object from being pickled."""
+    self.__dict__.update(state)
+    self.store = None
+
+  def authorize(self, http):
+    """Authorize an httplib2.Http instance with these Credentials
+
+    Args:
+       http - An instance of httplib2.Http
+           or something that acts like it.
+
+    Returns:
+       A modified instance of http that was passed in.
+
+    Example:
+
+      h = httplib2.Http()
+      h = credentials.authorize(h)
+
+    You can't create a new OAuth
+    subclass of httplib2.Authenication because
+    it never gets passed the absolute URI, which is
+    needed for signing. So instead we have to overload
+    'request' with a closure that adds in the
+    Authorization header and then calls the original version
+    of 'request()'.
+    """
+    request_orig = http.request
+    signer = oauth.SignatureMethod_HMAC_SHA1()
+
+    # The closure that will replace 'httplib2.Http.request'.
+    def new_request(uri, method='GET', body=None, headers=None,
+                    redirections=httplib2.DEFAULT_MAX_REDIRECTS,
+                    connection_type=None):
+      """Modify the request headers to add the appropriate
+      Authorization header."""
+      response_code = 302
+      http.follow_redirects = False
+      while response_code in [301, 302]:
+        # add in xoauth_requestor_id=self._requestor to the uri
+        if self._requestor is None:
+          raise MissingParameter(
+              'Requestor must be set before using TwoLeggedOAuthCredentials')
+        parsed = list(urlparse.urlparse(uri))
+        q = parse_qsl(parsed[4])
+        q.append(('xoauth_requestor_id', self._requestor))
+        parsed[4] = urllib.urlencode(q)
+        uri = urlparse.urlunparse(parsed)
+
+        req = oauth.Request.from_consumer_and_token(
+            self.consumer, None, http_method=method, http_url=uri)
+        req.sign_request(signer, self.consumer, None)
+        if headers is None:
+          headers = {}
+        headers.update(req.to_header())
+        if 'user-agent' in headers:
+          headers['user-agent'] = self.user_agent + ' ' + headers['user-agent']
+        else:
+          headers['user-agent'] = self.user_agent
+        resp, content = request_orig(uri, method, body, headers,
+                            redirections, connection_type)
+        response_code = resp.status
+        if response_code in [301, 302]:
+          uri = resp['location']
+
+      if response_code == 401:
+        logging.info('Access token no longer valid: %s' % content)
+        # Do not store the invalid state of the Credentials because
+        # being 2LO they could be reinstated in the future.
+        raise CredentialsInvalidError("Credentials are invalid.")
+
+      return resp, content
+
+    http.request = new_request
+    return http
+
+
+
 class FlowThreeLegged(Flow):
   """Does the Three Legged Dance for OAuth 1.0a.
   """
diff --git a/tests/test_oauth.py b/tests/test_oauth.py
new file mode 100644
index 0000000..4d56c26
--- /dev/null
+++ b/tests/test_oauth.py
@@ -0,0 +1,76 @@
+#!/usr/bin/python2.4
+#
+# Copyright 2010 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""Oauth tests
+
+Unit tests for apiclient.oauth.
+"""
+
+__author__ = 'jcgregorio@google.com (Joe Gregorio)'
+
+import unittest
+
+from apiclient.http import HttpMockSequence
+from apiclient.oauth import CredentialsInvalidError
+from apiclient.oauth import MissingParameter
+from apiclient.oauth import TwoLeggedOAuthCredentials
+
+
+class TwoLeggedOAuthCredentialsTests(unittest.TestCase):
+
+  def setUp(self):
+    client_id = "some_client_id"
+    client_secret = "cOuDdkfjxxnv+"
+    user_agent = "sample/1.0"
+    self.credentials = TwoLeggedOAuthCredentials(client_id, client_secret,
+        user_agent)
+    self.credentials.requestor = 'test@example.org'
+
+  def test_invalid_token(self):
+    http = HttpMockSequence([
+      ({'status': '401'}, ''),
+      ])
+    http = self.credentials.authorize(http)
+    try:
+      resp, content = http.request("http://example.com")
+      self.fail('should raise CredentialsInvalidError')
+    except CredentialsInvalidError:
+      pass
+
+  def test_no_requestor(self):
+    self.credentials.requestor = None
+    http = HttpMockSequence([
+      ({'status': '401'}, ''),
+      ])
+    http = self.credentials.authorize(http)
+    try:
+      resp, content = http.request("http://example.com")
+      self.fail('should raise MissingParameter')
+    except MissingParameter:
+      pass
+
+  def test_add_requestor_to_uri(self):
+    http = HttpMockSequence([
+      ({'status': '200'}, 'echo_request_uri'),
+      ])
+    http = self.credentials.authorize(http)
+    resp, content = http.request("http://example.com")
+    self.assertEqual('http://example.com?xoauth_requestor_id=test%40example.org',
+                     content)
+
+if __name__ == '__main__':
+  unittest.main()
diff --git a/tests/test_oauth2client.py b/tests/test_oauth2client.py
index 6832739..3c6e0ba 100644
--- a/tests/test_oauth2client.py
+++ b/tests/test_oauth2client.py
@@ -15,9 +15,9 @@
 # limitations under the License.
 
 
-"""Discovery document tests
+"""Oauth2client tests
 
-Unit tests for objects created from discovery documents.
+Unit tests for oauth2client.
 """
 
 __author__ = 'jcgregorio@google.com (Joe Gregorio)'