Go to the Down Hill level with the long pipes. When the game starts, immediately press pause. Perform the "high-speed motion" cheat. Then, when you go down the hill, go off the ramp closest to the wall near the pipes. Go off the ramp straight at the wall. If you got high enough you should be floating in the air and free to do any tricks you want. Infinite Air! *Note: I find it impossible to land after letting go of the controls.