Secret Bikes:
Get all golds in competitions and get every cover to unlock secret bikes in career mode.

Tony Hawk:
Get all 30 covers in career mode with any character to unlock Tony Hawk on an old girls bike.

Warehouse level from Tony Hawk's Pro Skater:
Score a 200,000 combo.

Burnside level from Tony Hawk's Pro Skater:
Beat the game with all characters.

Granny:
Pause game play, then press L1, Up, Square, X, X, Down, Circle.

8 Minutes Added To Your Time:
Pause the game and hold L1 and then press Square, Up, Circle, X.

Perfect Balance:
Pause the game and hold L1 and then press Square, Left, Up, Right.

Special Always Full:
Pause the game and hold L1 and then press Left, Down, Triangle, Circle, Up, Left, Triangle, Square.

10x Your Score:
Pause the game and hold L1 and then press Square, Circle, Circle, Up, Down, Down.

Grind Balance Bar:
Pause the game and hold L1 and then press Left, Circle, Square, Triangle, Square, Circle, X.

Big Tires:
Pause the game then hold L1 then press down Circle, Circle, Downs.

Unlock GT Dyno W/ Jet Pack To Do Any Trick Without Falling Off:
In freestlye choose Matt Hoffman with any bike. Then pause press Left, Right, L, R, Up, Down, X, Circle, Square.

Moves:

Backflip-
Press Right, Down, Square. 

Double Tailwhip- 
Press Down/Right + Circle when launching off a ramp, but not in a halfpipe.

Flair- 
Press Down, Square, then do a 180.

Indian Air- 
Press Up/Right + Circle, but not in the halfpipe.

Rocket Queen- 
Press Down/Right + Square.
 
Single Tailwhip- 
Press Down/Left + Circle while launching off a ramp, but not in a halfpipe.
 
Superman- 
Press Up/Left + Circle while in the air.

Mat Hoffman
Backflip Tailwhip: Press Up, Down, Circle. 
Bar Hop: Press Right, Right, Square.
One-handed Superman: Press Down, Down, Circle. 
Peacock: Press Left, Right, Square.
Triple Tailwhip: Press Down, Right, Circle. 

Tony Hawk
Superman Tailwhip:  Down,Down,Circle 
Front Body Flip:  Down,Up,Circle
Body Varial:  Left,Right,Square
Decade Air:  Left,Right,Circle

Mike Escamilla
Body Varial: Press Left, Right, Square. 
Front Flip: Press Down, Up, Circle. 
Backflip Onefoot:  Up, Down, Circle
Superman Seatgrab Barspin:  Down, Down, Circle


Cory Nastazio (Nasty)
Front Flip: Down, Up, Circle.
Double Tailwhip: Press Down, Right, Circle. 
Backflip Tabeltop: Up, Down, Circle.

Joe Kowalski (Butcher)
No Footed Candybar One Hander: Press Up, Up, Circle.
Half Barspin Tailwhip: Press Down, Right, Circle. 

Rick Thorne
Front Body Flip: Press Down, Right Circle.
Decade Air: Press Left, Right, Circle. 

Dennis McCoy (DMC)
Decade Air: Press Left, Right, Square. 
Double Tailwhip: Press Down, Right, Square. 

Kevin Robinson
One Handed Swing Leg: Press Right, Down, Square. 
Bar Hop: Press Right, Right, Square. 

Simon Tabron
No Footed Candy Bar One Hander: Right, Down, Square.
Double Seat Grab Superman: Press Down, Down, Circle. 
One Handed Swing Leg: Right, Right, Square. 
Backflip one footer: Up, Down, O.
Superman seat grab: Up, Up, O.


Granny
Gum grab: Up, Up, Square
Superman seat grab: Up, Up, Circle

Thanks to Revolution readers Josh Scott, Justin C., faulker, kevin waller, aron Ferguson, Adam Reisde, Mat 409, Aaron Ferguson, and mike santorelli!