Membership Provider to Allow Social Networking Sites Login

I recently created a custom membership provider to my asp.net (4.0) site and a custom role provider so that I have total control over custom attributes or properties for members of my site. BUT, I also want to allow users to "sign-up" to be a member of my site via using one of the OpenId providers like on StackOverflow. Can anyone point me in the direction of how to get started on this?

I've already signed up for an openId account 开发者_StackOverflow社区for my domain and they recommend Jarain Engage for implementation of the various social networking sites providers but I would prefer to use something that I develop myself and add providers when I'm ready for them.

This feature is coming in WebPages 2 which will likely be released with ASP.NET 4.5 see the following link:

http://www.asp.net/web-pages/overview/whats-new/top-features-in-web-pages-2-developer-preview#oauthsetup.

It is still a little away (only CTP right now and a beta probably landing in the next few weeks) but definitely worth a look as the implementation looks very straightforward.