Though the game I have in mind is turn-based, it isn't exactly what I would call asynchronous. I think what I need to know above all else is whether there is a way for two phones to communicate over wifi or 3g that I could take advantage of in my game. I've been looking at Game Kit, but it seems to be emphasizing "close proximity." Could this leverage 3g or would the players actually have to be near each other?
Thanks for the feedback, but I was looking at something less like matchmaking and more like Words with Friends, wherein you play only with people that you already know. I was thinking of using facebook integration for that. What I really need to know is just how to send information directly from one phone to another, if that's possible. Sorry if I was unclear in my original post.