Example of good login/registration integration with social networks and openid?

We are at the early stages of creating a new website, at the point where we need to build the login/registration module.

I want to be looking forward to the future, so I want to allow my users to register and login using all sorts of accounts, such as OpenID, Google, Facebook, Y开发者_C百科ahoo, etc ...

My users are not all tech savvy, do you have an example of a site that managed to successfully implement a user-friendly "universal" login system?

Thanks

https://stackoverflow.com/

:-)

The only confusing this is the box where you can type in any provider. (Dig that one away under an other heading).