Foursquare and Loopt have put location-based social networks on the map, and have potentially created a viable business model as well. Now there's a new kid on the block, called Stalqer, which best described as a Foursquare on steroids. The iPhone app, which will be free, should hit the app store in the next few hours. In theory, Stalqer is very similar to Foursquare in that it tracks your and your friends' locations and broadcasts this information via the application and through push notifications. But one of the key differentiators is the fact that Stalqer updates the location in the background, which Foursquare, and most other apps, don't do at the moment. This is because the device does not allow third party apps to run in the background. But Stalqer has found a way to record your location without you having to actually open up the application. So how does Stalqer do it?