|I've been thinking about adding ranks and a "highscore" board for some time now.|
Currently I'm evaluating OpenFeint, which seems to establish itself as the de-facto standard for "social gaming" on the iPhone. It looks like a good option, because it features global highscore lists, individual highscore lists (e.g. for a group of friends), achievements (one could track his or her first safe, good and perfect landing, for example) and lots of other cool stuff.
I've just begun browsing through the API, but it even seems to be possible to attach binary data to highscores. Now I've always planned to add an option to "save" replays (yes, once the replays are available, I know ) - and this would be an interesting way of sharing these replays: You could download the replay e.g. of the best landing so far and watch it on your own iPhone or iPod. Or run a competition among your friends and share the replays later.
That said, I can't promise anything and I'll have to check if all this would actually work. But to me this sounds very promising and very interesting, so I'll definitely look into it.
I'll keep you up to date...