There's some racing game where you blow in it to make your car go. I don't think it's good but it uses the mic...
Well most of the people who are in for gaming have the Touch. And since the Touch dose not have a built in mic it makes no sense to input that function into a game, because many people won't buy a mic. And until some sweet game comes out that truly utilises(gawd i cant spell this word) the mic in the actual gameplay and starts a new trend of mic infused games, we wont see many games that use the mic. I just bought an apple mic/earphone set, but only for the music controls. Apple should include this with Touch's instead of regular headphones.
iBBQ - Fire it Up! (you can blow air thru the microphone to increase strength of fire) http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=310000507&mt=8
Well, I think it is kinda handy. Without it, the people I call with couldn't hear me that good. Hmm, or they would have to stand next to me, but in that case I wouldn't have to call them anyway Oh, and that Zippo app reacts to blowing... Isn't really a game tho
The iphone's voice recognition is surprisingly good. How freaking awesome would it be to have movement controlled by dpad, and use the other hand to tap the screen where you want to target and simply call out your spell, and have the iphone recognize it. This would allow a vastly greater array of attacks (fireball, cone of cold, curse, possess, chain lighting, whatever!) and vastly easier switching between attacks then one could manage without voice. I'm sure its probably not technically possible for some reason, but the hardware and voice recognition are in the device