Hack the game with an action replay to moon jump. Start the game, and enter a level on the red coins star (any level will do). Then speak to the bob-omb who shows the red coin locations on the map. Tap b while speaking to him and you'll moonjump, then just press a till he stops speaking. Then you'll fall to the ground and undoubtedly hurt yourself, but the red coin locations will be permenantly on the map screen. Plus, now, as long as you don't quit, or switch off your DS, you can see the red coin locations in any level, not just the level you did the technique in, as long as you're on the red coin star. Good luck!