Other contributors have said "What are the cheats for spiderman 3?" is the same question as "What are the cheats for spider-man 3?" If you believe that these are not asking the same thing and should be answered differently, click here
This is not a cheat more like a glitch. Go in the city start jumping around the place for a while. Then open the ps2 and take the game out and close the thing again. Nothing will happen at first, but...