I am developing a rails 3 app that needs to have to a facebook "like" button and display the profile pictures of the people who have click it and complete the liki
Attach to the Facebook javascript event using FB.Event.subscribe
FB.Event.subscribe('edge.create', function(response) {
// fire an ajax call to store that the user has liked you
});
edge.create -- fired when the user likes something (fb:like)
http://developers.facebook.com/docs/reference/javascript/FB.Event.subscribe