You need to create a Facebook application in yoru facebook "developers" settings.
Facebook will give you a lot of information, and a "token". in IP's ACP, you can enter your "Facebook token"
I have this Facebook application, actually I have already installed this in my old forum. But I don't know how to put it in some different areas of this forum...
Re: I'd Like To Add A Facebook Conect In The Register/Login Page
I've changed my mind... I was thinking that is better without facebook connect because the lenght of the nicks... Usually they are very long in Facebook account, what do you think?