I had previously thought that Facebook Connect and 'Login with Facebook' were separate things, but after reading this I changed my mind:
... features of Connect (login, profile integration, Feed, friend linking) ...
From: http://wiki.developers.facebook.com/index.php/User:Facebook_Connect_Live_Sites
Is it correct that 'Login with Facebook' is a subset of Facebook connect?
What exactly are those features of connect - eg what does 'feed' entail?
How can I tell which features of Connect an app is using when I sign in with Facebook? Would it all be contained in the 'Request for permission' dialog?