holy damn why didn't i think of this in modnation racers...
Modnations racers is a game based off of the possibilities of creation that littlebigplanet possesses, except in just race form. Instead of making levels, you make racetracks, instead of making your sackboy uke or tori, you make your mod uke or tori, Instead of a pod, you have that racers square or whatever it is.
Fun game, and great idea.