Facebook Places is now official! May it be a popular vacation spot, a museum or a bar, let your friends know where you are using your mobile device and eventually meet them if they are in the same place ! You will need the latest version of Facebook application for iPhone or just your mobile browser if it can support HTML 5 and geolocation. For now, Facebook Places is only available in the United States.

To geotag yourself, go to Places and click "check in". You’ll see a list of places around your area. If you can’t find your exact location, search or add it. Facebook will update your friends via Newsfeed and in that place’s Recent Activity. You’ll see who else is in the same place in the “People Here Now” section. This can be viewed only for a limited amount of time and only to those who are checked in. If you don’t wish to be visible, uncheck the “Include me in ‘People Here Now’ after I check in” in the privacy control.

You can also tag some friends who are with you just as you would in a status or photo. If they approve it, they will be checked in too, if not, they will simply be tagged. You can disable people from checking you in places in the Privacy Control by turning off the “Let Friends Check Me In” setting. Also, only friends can see you as you visit or when you’re tagged in a place unless you set the master privacy control to "Everyone". You also have the liberty to remove yourself from a tag. Everything is all up to you.

If you’re in for something more exciting, add a third party application. As usual, these applications will need your permission before they can acquire information and your friends can share your check-ins in the applications they use. If you want to stop sharing, simply uncheck "Applications and Websites" in your Privacy Settings

Facebook just added another feature for socialization to be more exciting as it further shrinks the world into your palm.

[Editor’s Note: For John’s thoughts on the announcement and our live blog coverage via the comments, please see our previous posts. Screenshots available below.  As a special bonus, I’ve included my video from March where I predicted this very thing. –mrh]