At the main menu, highlight the "Options" selection. Then, hold L1 + Right and press Triangle(2), Circle, Triangle.
Game Shark Codes
Master Code (Must Be On) EC8783AC 14451B9C
Unlock Kid Mode Cheat 4CA3FF38 1456E7A6
Unlock Always Special Cheat 4CA3FF3C 1456E7A6
Unlock Perfect Balance Cheat 4CA3FF40 1456E7A6
Unlock Super Spin Cheat 4CA3FF44 1456E7A6
Unlock Half Gravity Cheat 4CA3FF48 1456E7A6
Unlock Quickie Tricks Cheat 4CA3FF4C 1456E7A6
Unlock Double Speed Cheat 4CA3FF50 1456E7A6
Unlock Big Head Cheat 4CA3FF54 1456E7A6
Unlock Metallic Boarder Cheat 4CA3FF58 1456E7A6
Unlock Flipside Cheat 4CA3FF5C 1456E7A6
Unlock All Movies 4CA3FF00 1456300C
Unlock Rooftop Level 4CA30290 1456E7A6