各种实现：http://oauth.googlecode.com/svn/code/
Twitter OAuth : https://dev.twitter.com/docs/auth/oauth
Facebook OAuth : http://developers.facebook.com/docs/authentication/
http://www.richardnichols.net/2010/06/implementing-facebook-oauth-2-0-authentication-in-java/
OpenX OAuth API
1. PHP : https://github.com/openx/OX3-PHP-API-Client