Filed under: iPhoneOpenFeint has announced that they've reached 25 million users on their social networking service for apps on the App Store. That's an astounding number, and not only does it represent an amazing achievement by the folks at Aurora Feint, but it hints at just how big Apple's official Game Center service will be (whenever they get around to, you know, implementing it). Just for comparison, location networking service Foursquare is still racing to try and hit 3 million users, so in
