Enter the following codes on the cheats menu: 

Unlock All Create-a-Skater Items: 
gethotgear
Unlock Lion King Video: 
savannah
Unlock Tarzan Video: 
nugget
Unlock Toy Story Video: 
marin
Special Meter Always Full: 
happyfeet 

Unlock Better Stats: 
Collect hidden gems in each level to improve your stats. 

Unlock Special Moves: 
Collect 25 items in each level.