stackoverflow (which was the only place i used this) have their own provider that you can switch to - http://blog.stackoverflow.com/2011/05/stack-exchange-is-an

stackoverflow (which was the only place i used this) have their own provider that you can switch to - http://blog.stackoverflow.com/2011/05/stack-exchange-is-an-openid-provider/ http://blog.stackoverflow.com/2011/05/stack-exchange-is-an-o...