At Facebook’s Places event earlier tonight, they noted that their iPhone app would be updated tonight with the new check-in functionality. Sure enough, here it is. Though the App Store update alert hasn’t kicked in yet, if you go to the actual page and redownload it, it should be the latest version (version 3.2).
The program for mobile phones will lets its users share where you are with your friends, see where your friends are and discover new places around you
Update: A number of people in the U.S. are also reporting seeing messages that Places isn’t available in their area yet. It appears that Facebook is slowly rolling this out. Stay tuned.
Update 2: I’ve just spoken with Facebook and they informed me that even though the app is live, the Places functionality isn’t rolled out to everyone just yet. That’s why some people see the message that it’s not available in their area — and why others can’t yet check-in. Facebook wants to make sure their servers can handle the load that is inevitably coming so it will be a roll out over the next day or two I’m told.