iRwego is an app that is very intuitive and can make you feel like your in a Mario world. The idea behind the app is to put the iPhone in your pocket and let the accelerometer do the rest of the work. You jump and the iPhone makes the popular jumping sound. When you crouch down you will hear the “worp worp worp” sound as if you are going down the green pipe. If you play Mario you know the other sounds it’ll make. I haven’t tried it out but it sounds like a great fun app for any Mario lover.
I wouldn’t count on it lasting too long though as Nintendo owns the Mario image.