How to integrate facebook login button in my rails 3 app

What is the easiest and reliable way to add facebook login button to my rails 3 app?

I Currently have a User model with email 开发者_如何学Cand password_hash and password_salt

Are there any good gems that make this easy in rails3?

Are my only options OmniAuth and Devise? I am currently using authenticating from scratch method from railscasts: http://railscasts.com/episodes/250-authentication-from-scratch

OmniAuth is the easiest and fastest choice, in my experience. Devise is great but much more heavyweight if all you're planning to do is Facebook OAuth.