Not a Facebook developed app, but one that should have been there Day 1 and one that will more than likely be rolled into the core offering sooner than later.
Until then, head over to the Social Hangouts Facebook app here
The app was just released this past Saturday, so it hasn’t propagated across the whole Facebook ecosystem yet, but major shoutout to AllFacebook for picking up on this.
From the press release…
(Social Hangouts) a multi-user video chat application on Facebook is now ready to take on the millions of Facebook users in a click of a button. Social Hangouts is a simple, easy to use application; you access the app without ever leaving Facebook, invite up to 20 of your contacts from your friends list and you could all be having a live video chat in no time! This might prove to be in Facebook’s favor, who to-date has managed to stay on top due to application and developers such as these and add to its arsenal against Google+.
Have fun !