Cycling motivator

Hi all,

My little cousin has an autistic disorder and his PT is trying to encourage him to use his tricycle more, but he doesn't seem to be motivated (he pedals for few seconds and stop). I would like to try adding some cool stuff on his tricycle to make pedaling more fun (like a bubble gun, leds or a mp3 player). Could you point out at me some projects that have mp3 players, led or bubble guns that activate with the pedaling motion?

Thanks!

What about a batman light or something like that pointed at the ground a few feet ahead of his trike? You can add arduino and magnetic sensor to the fork and a magnet to the wheel. This gives me ideas. I could try that for my son.