A pretty neat glitch I found by accident the other day. If you press and hold jump just before entering a speeder bike (like, a few frames), you do a super jump. If you ride this off the screen and then begin mashing the "A" button, you just never come back down. In this case I can still collect powerups, but I can also get hit by the obstacles. I somehow can't jump the fence so it's a useless tactic. On one attempt, I managed to wrap around to the floor but then I hit the fence again. Interesting.