"Foursquare gets all the hype." It's something I hear just about every day from just about every other location-based startup. And it's true, though I would argue that it's warranted -- and investors seem to agree . But it's also important to keep some perspective. While Foursquare is just shy of 2 million users, other services like MyTown have quickly surpassed that number . Same with Google Latitude, which is at 3 million . And you can put Loopt on that list as well, as today they've hit 4 million total users. Loopt was one of the first location-based services to get a lot of hype -- even getting on stage at the Apple event first talking about the App Store way back when. But as we've noted numerous times, they started out at a disadvantage because the iPhone didn't allow third-party apps to run in the background. And that was Loopt's model, continuous location updates. But with iOS 4, the iPhone does finally allow for that functionality -- and specially for background location. And Loopt is benefiting from it.