diff --git a/Web/Authenticate/Facebook.hs b/Web/Authenticate/Facebook.hs
--- a/Web/Authenticate/Facebook.hs
+++ b/Web/Authenticate/Facebook.hs
@@ -4,10 +4,13 @@
 module Web.Authenticate.Facebook
     ( Facebook (..)
     , AccessToken (..)
+    , getForwardUrlParams
+    , getForwardUrlWithState
     , getForwardUrl
     , getAccessToken
     , getGraphData
     , getGraphData_
+    , getLogoutUrl
     ) where
 
 import Network.HTTP.Enumerator
@@ -27,6 +30,7 @@
 import Network.HTTP.Types (renderQueryText)
 import Data.Monoid (mappend)
 import Data.ByteString (ByteString)
+import Control.Arrow ((***))
 
 data Facebook = Facebook
     { facebookClientId :: Text
@@ -38,19 +42,28 @@
 newtype AccessToken = AccessToken { unAccessToken :: Text }
     deriving (Show, Eq, Read, Ord, Data, Typeable)
 
-getForwardUrl :: Facebook -> [Text] -> Text
-getForwardUrl fb perms =
+getForwardUrlParams :: Facebook -> [(Text, Text)] -> Text
+getForwardUrlParams fb params =
     TE.decodeUtf8 $ toByteString $
     copyByteString "https://graph.facebook.com/oauth/authorize"
     `mappend`
     renderQueryText True
-        ( ("client_id", Just $ facebookClientId fb)
-        : ("redirect_uri", Just $ facebookRedirectUri fb)
-        : if null perms
-            then []
-            else [("scope", Just $ T.intercalate "," perms)])
+        (  ("client_id", Just $ facebookClientId fb)
+         : ("redirect_uri", Just $ facebookRedirectUri fb)
+         : map (id *** Just) params)
 
+-- Internal function used to simplify getForwardUrl & getForwardUrlWithState
+getForwardUrlWithExtra_ :: Facebook -> [Text] -> [(Text, Text)] -> Text
+getForwardUrlWithExtra_ fb perms extra = getForwardUrlParams fb $ (if null perms
+                                                                   then id
+                                                                   else (("scope", T.intercalate "," perms):)) extra
 
+getForwardUrlWithState :: Facebook -> [Text] -> Text -> Text
+getForwardUrlWithState fb perms state = getForwardUrlWithExtra_ fb perms [("state", state)]
+
+getForwardUrl :: Facebook -> [Text] -> Text
+getForwardUrl fb perms = getForwardUrlWithExtra_ fb perms []
+
 accessTokenUrl :: Facebook -> Text -> ByteString
 accessTokenUrl fb code =
     toByteString $
@@ -91,3 +104,12 @@
 data InvalidJsonException = InvalidJsonException String
     deriving (Show, Typeable)
 instance Exception InvalidJsonException
+
+-- | Logs out the user from their Facebook session.
+getLogoutUrl :: AccessToken
+             -> Text -- ^ URL the user should be directed to in your site domain.
+             -> Text -- ^ Logout URL in @https://www.facebook.com/@.
+getLogoutUrl (AccessToken s) next =
+    TE.decodeUtf8 $ toByteString $
+    copyByteString "https://www.facebook.com/logout.php"
+    `mappend` renderQueryText True [("next", Just next), ("access_token", Just s)]
diff --git a/Web/Authenticate/OAuth.hs b/Web/Authenticate/OAuth.hs
--- a/Web/Authenticate/OAuth.hs
+++ b/Web/Authenticate/OAuth.hs
@@ -128,7 +128,10 @@
 authorizeUrl :: OAuth           -- ^ OAuth Application
              -> Credential      -- ^ Temporary Credential (Request Token & Secret)
              -> String          -- ^ URL to authorize
-authorizeUrl oa cr = oauthAuthorizeUri oa ++ BS.unpack (renderSimpleQuery True [("oauth_token", token cr)])
+authorizeUrl oa cr = oauthAuthorizeUri oa ++ BS.unpack (renderSimpleQuery True queries)
+  where queries = case oauthCallback oa of
+                    Nothing       -> [("oauth_token", token cr)]
+                    Just callback -> [("oauth_token", token cr), ("oauth_callback", callback)]
 
 -- | Get Access token.
 getAccessToken, getTokenCredential
diff --git a/authenticate.cabal b/authenticate.cabal
--- a/authenticate.cabal
+++ b/authenticate.cabal
@@ -1,5 +1,5 @@
 name:            authenticate
-version:         0.10.3.1
+version:         0.10.4
 license:         BSD3
 license-file:    LICENSE
 author:          Michael Snoyman, Hiromi Ishii, Arash Rouhani
@@ -11,7 +11,7 @@
 stability:       Stable
 cabal-version:   >= 1.6
 build-type:      Simple
-homepage:        http://github.com/snoyberg/authenticate/tree/master
+homepage:        http://github.com/yesodweb/authenticate
 
 library
     build-depends:   base >= 4 && < 5,
@@ -54,4 +54,4 @@
 
 source-repository head
   type:     git
-  location: git://github.com/snoyberg/authenticate.git
+  location: git://github.com/yesodweb/authenticate.git