Facebook now has a Check-in Feature

On the heels of Foursquare and Gowalla, Facebook now has a check-in feature of its own.

Facebook executives on Wednesday announced the launch of Facebook Places, which -- similar to services such as Foursquare and Gowalla -- will allow people to use the GPS on their mobile phones to let friends know exactly where they are.

Facebook Places is available immediately in the United States through the latest version of Facebook's iPhone app and through the company's site for advance mobile devices.

Foursquare has become the clear leader or check-in apps and a darling of tech media, even as it looks for ways to turn a profit. Boasting a half-million users at the start of SXSW, Foursquare doubled that in about a month then needed only another three months to reach 2 million users.

In regards to check-in apps, users "check in" at restaurants, bars, movie theaters or just about anywhere else they visit. The idea is twofold -- to let friends know what you're up to while racking up points and earning virtual badges in the application's gaming element.

The potential for Facebook Places is huge.  With a half-billion users, if Facebook doesn't blow it, they should be able to take this area over.  We''ll have to see what early reviews look like and how fast it starts taking off.