Facebook Connect easily lets developers make their websites and desktop applications more social. If you develop apps for the iPhone and iPod Touch, you can now start making those apps more social with the launch of “Facebook Connect for iPhone,” including:

• Making API calls so your app can access users' profiles and share information on Facebook.
• Publishing to Facebook via Feed forms.
• Asking users for extended permissions, like offline access, so you can still interact with their data when they're offline.

More info: Download | Documentation