diff --git a/README.rst b/README.rst
index dda6bbd..ba86c3f 100644
--- a/README.rst
+++ b/README.rst
@@ -44,6 +44,10 @@ Creating a request
     >>> from github2.client import Github
     >>> github = Github(username="ask", api_token=".......")
 
+Or for an unauthenticated connection
+
+    >>> github = Github()
+
 Users
 =====
 
diff --git a/github2/client.py b/github2/client.py
index 6378604..c3e77cd 100644
--- a/github2/client.py
+++ b/github2/client.py
@@ -6,7 +6,7 @@ from github2.commits import Commits
 
 class Github(object):
 
-    def __init__(self, username, api_token, debug=False):
+    def __init__(self, username=None, api_token=None, debug=False):
         self.debug = debug
         self.request = GithubRequest(username=username, api_token=api_token,
                                      debug=self.debug)
diff --git a/github2/request.py b/github2/request.py
index 3cb6542..233a04f 100644
--- a/github2/request.py
+++ b/github2/request.py
@@ -24,7 +24,7 @@ class GithubRequest(object):
         "https": httplib.HTTPSConnection,
     }
 
-    def __init__(self, username, api_token, url_prefix=None, debug=False):
+    def __init__(self, username=None, api_token=None, url_prefix=None, debug=False):
         self.username = username
         self.api_token = api_token
         self.url_prefix = url_prefix
@@ -37,8 +37,11 @@ class GithubRequest(object):
             }
 
     def encode_authentication_data(self, extra_post_data):
-        post_data = {"login": self.username,
-                     "token": self.api_token}
+        if self.username and self.api_token:
+            post_data = {"login": self.username,
+                         "token": self.api_token}
+        else:
+            post_data = {}
         post_data.update(extra_post_data) 
         return urlencode(post_data)