OAuth2.0
新浪
http://code.google.com/p/oauth-dot-net/
http://www.cnblogs.com/mainz/archive/2010/12/01/1893718.html
http://www.cnblogs.com/prolifes/articles/2263033.html
http://www.cnblogs.com/shiningrise/archive/2012/01/01/2309725.html
QQ:
http://qqconnect.codeplex.com/
https://github.com/shiningrise/dotnetopenid