This could be a case of me just not coming across the right games, but it seems to me the ideas and possibilities of multi-touch functionality is barely used in iOS games. I feel like a lot of games are just trying to stick a traditional "controller" interface onto their games instead of taking advantage of the intrinsic touchy goodness! Are there some games I just havent noticed? I was thinking how cool it'd be to make a game thats sort of like Breakout but you can stretch and tilt your paddle at any angle. Or controlling a big ghost-buster like raygun that you can twist using a second finger. Just some thoughts....
It's a lot harder than it looks to use this feature without it feeling contrived. Eliss is the most obvious implementation of multitouch gestures in a successful game. Cross Fingers, by Mobigame, requires multitouch for some delicate operations. Cut the Rope has some maneuvers where you must synchronize two gestures with both hands/thumbs to catch all three stars. This topic would fit better under "General Game Discussion".
I was thinking about the possibilities of developing something along these lines. Thats why I posted it here, but I can see what you mean about it being general.