While third parties have developed several of their own social gaming networks for the iPhone and iPad, Apple entered the space themselves today with iPhone 4.0 and their Game Center Social Network. (Think Microsoft Xbox Live or Sony Playstation Network for iPhone and iPad apps).
Features include inviting friends, matchmaking, leader-boards, and achievements. And because it's built into the OS, developers get it "for free". Hard to compete with that...
[Image via Gizmodo]