I have a Rails 3 application using Devise for authentication. Now I need to allow someone to log in using their Facebook account. I think this is called Facebook Connect, but I've also heard the term Facebook Graph API, so I'm not sure which one I'm asking for.
What do I need to do in order to integrate Facebook Connect with Devise?
This question is pretty old now. A year ago, Devise v1.2 introduced OmniAuth support. Now Devise is at v2.1 (as of this writing) and using OmniAuth is even easier. Here is a great tutorial from the Devise wiki on using the
omniauth-facebook gem with Devise to allow sign-in using Facebook.
Also check out this great tutorial on registering your application and working with the Facebook Graph API.