I'm building a iPhone App, that communicates with a webserver (Java webapp) using REST (XML over http). In my prototype I used http's basic-authentication to allow access and identify the user, using username and password. Since there should be friendships and profiles in my app, I want to use facebook-connect so I don't have to implement it and the users don't have to manage there friends and profiles twice. When I use fb-connect, I may even go without all the basic user management stuff, like create a new user, change password and so on.
So here is my question: Is it possible to use facebook-connect as my one and only user authentication? And more importantly: How can I authenticate the user while communicating with the webserver?
To clarify: I don't want to link the facebook account to my user accounts, I want to use it instead.