Sorry this doesn't directly answer your question, but... for this kind of remote authentication people seem to have put most effort into Janrain. This includes support for:
Aol, Yahoo!, Facebook, Twitter, LinkedIn, Google, MySpace, Windows Live, PayPal, Hyves, Verisign, MyOpenID, OpenID, Flickr, Blogger, Livejournal, Wordpress and Netlog. You will find that Janrain is better supported on the list too. Regards, D
