Cheat Mode:
At the options screen hold R2 and press Up, Up, Down, Down, Left, Right, Left, Right, , , , . This brings up the Cheat Name screen, where you can enter the following:

Code        Result
TopBird     Stay on Jet-ski
AllOutAI    Harder AI
Festival    All rider movies
AllChar     All characters
Peepshow    All characters including steve and the Bermuda Triangle level
Passport	All courses
LaPinata    All character swinsuits (each has about 10)

Level 1 Tricks:
Cordova - L2 + Up
Lazy Boy - L2 + Down
Heart Attack - L2 + Left
Double Cancan - L2 + Right
Spade - R1 + Up
Rollover - R1 + Down
Saran Wrap - R1+ Left
Seat Surf - R1 + Right
Handlebar Handstand - R2 + Up
Superman - R2 + Down
Nac Nac - R2 + Left
Shin Grab - R2 + Right

Level 2 Tricks:
Air Walk - L2 + Up, Down, Up
Cliffhanger - R2 + Down, Up, Down
Rack - R2 + Up, Up, Down
Whirlybird - R2 + L3 (move in a circle in counter clockwise direction starting at top)
Metronome - R2 + L3 (half circle in counter clockwise direction starting at left and ending at right)
Roundhouse - R1 + L3 (half circle in counter clockwise direction starting at right and ending at left)
Tumbleweed - R1 + down + L3 (half circle in counter clockwise direction starting at top and ending at bottom)
Doubledouble Cancan - R2 + Right, Left, Right
Rear Handstand (R1 + R2) + Down, Up, Down
Bicycle Kick - R2 + right + L3(half circle in counter clockwise direction starting at left and ending at right)

Level 3 Tricks:
Backflip (R1 + R2) + Down, Down
Pommel Horse - R1 + Right, Left, L3(full circle, counter clockwise starting at bottom)
Wu Ping Crane - R2 + Up, Down, L3(full circle, counter clockwise starting at top)

GameShark Codes

(M)Must Be On  
ECB15E9C141B74EC
  
Unlock Andy's Movie  
4CF585501456E7A6  

Unlock Haily's Movie  
4CF585541456E7A6  

Unlock Juana's Movie  
4CF585581456E7A6  

Unlock Sebastian's Movie  
4CF5855C1456E7A6  

Unlock Rafael's Movie  
4CF585601456E7A6  

Unlock Amman Ra's Movie  
4CF585641456E7A6  

Unlock Kyoko's Movie  

4CF585681456E7A6
  
Unlock Jeremy's Movie  
4CF5856C1456E7A6  

Seoul Open Arcade Mode 
4CF582A01456E7A6  

Lake Quilotoa Open Arcade Mode 
4CF582A41456E7A6  

Nice Open Arcade Mode 
4CF582A81456E7A6  

Loch Ness Open Arcade Mode 
4CF582AC1456E7A6  

Madrid 2 Open Arcade Mode 
4CF582B01456E7A6  

Kuta Beach Open Arcade Mode 
4CF582B41456E7A6  

Tokyo Open Arcade Mode 
4CF582B81456E7A6  

Nile River Open Arcade Mode 
4CF582BC1456E7A6  

Seoul 2 Open Arcade Mode 
4CF582C01456E7A6  

Venice Open Arcade Mode 
4CF582C41456E7A6  

Bering Straight Open Arcade Mode 
4CF582C81456E7A6  

Amazon River Open Arcade Mode 
4CF582CC1456E7A6  

Lake Havasu Open Arcade Mode 
4CF582D01456E7A6  

Thanks to Revolution readers Orca, Rich Gouge, Dan and Brian Burow!