it can be split-screen games like lightbike ( http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=303305282&mt=8 ) or a game where you pass the idevice back and forth any help is greatly appreciated -applesauce
slotz racing up to four players on one device. i dont know how fun it is but if you get frustrated it will be easy to headbutt all three of your opponents at once with everyone being huddled around the little iphone and everything.
I think I have to say "Age of Curling", since the basic idea behind the game was to make something nice to play during long train-rides...