Facebook has announced that it is taking a leap into location-based apps with the launch of Facebook Places. The tool should be of interest to marketers as it takes the geo-social marketing potential of foursquare, which Brafton has reported is boosting brand awareness of for a number businesses, and extends it to Facebook's 500 million users.

Michael Sharon, the Facebook product manager for Places, explains that users can share their locations by "checking in" to find friends or simply update connections on their whereabouts. The tool is available through the latest version of the Facebook application for iPhone or it can be downloaded for other mobile-ready phones at touch.facebook.com. Facebook Places will be accessible via mobile devices or on the traditional web.

Businesses may be interested to know that when users check in, their friends can see them at a Place Page on Facebook. Facebook explains that this page shows a map of the location, a list of friends who are there, a list of friends who have previously checked in at this destination and activity streams of people who are there. This makes for real-time word-of-web referrals about locations, similar to the value of Twitter Places, which Brafton wrote about earlier this year.

Another important feature of Facebook Places is that it is armed with rigid privacy controls. Users can allow or prevent friends from tagging them at places, control who sees their locations or remove location tags through mobile devices or desktops. By visiting their accounts' privacy settings, users have the ability to be as visible (or invisible) at check-ins as they wish.

Notably, Facebook Places' competitor, foursquare, announced it was ramping up its privacy features one day prior to the launch of Facebook's location-based app. Many speculate that in spite of foursquare's efforts to better serve users, it will become a footnote once Facebook Places takes off.

This may prove the case, as we've reported that foursquare and other geo-social tools have been slow to penetrate the U.S. consumer base, and myriad Facebook lovers are already touting Facebook Places as their new favorite app. On the site's official blog, more than 13,000 users "liked" the Facebook Places announcement at press time.

Still, there may be a loyal foursqaure audience worth hitting. One commenter on Facebook wrote, "this is a bootleg foursquare." It seems foursquare is telling geo-social users – and marketers – it still serves a unique role. Search Engine Land reports that foursquare officials spoke at the Facebook Places launch to emphasize that gaming is what differentiates foursquare. It will be interesting to see if Facebook Places moves in the gaming direction as it evolves.

An eMarketer report shows that the mobile gaming market will exceed $800 million in 2010 and ad support will drive 12.3 percent of the platform's revenue by 2014, so marketers may not want to cast foursquare campaigns aside just yet – and they should look to see what Facebook Places and other social networks offer in this realm.