Is it possible to set up a login database on a website that will allow the user to login/register with their Facebook account?
I've been asked by a client if this would be possible and my initial response was a bit skeptical. They want a website (that I'm creating) with normal registration/login option, but wants to know if it's also possible to add the option of giving users the ability to register/login using their Facebook account.
Would this require a certain type of integration with a specific Facebook page/fan page? What about logging in with a Twitter account?