Facebook 3.1 for iPhone is out with push notifications, world productivity drops 10%

Update: We’re hearing reports that the Facebook app is reaping havoc on contacts.  You might want to hold off on syncing until this is straightened out.

Update 2: A new version is already out that addresses this issue

All kidding aside, we suppose that it’d be good to know when someone direct messages you in Facebook – or something.  More importantly, Facebook now also lets you sync your addressbook contacts with your Facebook friends which could be beneficial for when people change email/phone/address/etc.  Or maybe you don’t need those people you hated in high school in your addressbook?

You’ll recall that Facebook’s lead iPhone developer, Joe Hewitt recently quit over his concerns with the App Store review process to focus on Web Apps. It looks like someone else was able to fill his shoes…

Download it from the App Store here.