Master cheat:
At the Main menu, quickly press Triangle, Circle, Triangle, Circle, Triangle, Square, Triangle, Square. This will unlock all cheats.

Level select:
In Career mode, pause the game. Now hold R1 and press Triangle, Left, Left, Triangle, Circle, Up, Up, Square.

Unlock All Italian Job Mode missions:
At the Main menu, quickly press Circle, Circle, Triangle, Square, Square.

Unlcok All Challenge Mode missions: Quickly press
At the Main menu, quickly press Square, Square, Triangle, Circle, Circle, Square, Triangle, Circle.

Unlock All Checkpoint missions:
At the Main menu, quickly press Circle, Square, Triangle, Square, Triangle, Square, Triangle, Square, Circle.

Unlcok All Destructor missions: Quickly press
At the Main menu, quickly press Triangle, Square, Square, Triangle, Square, Square, Triangle, Circle, Circle, Circle.

Unlock All Free Ride missions:
At the Main menu, quickly press Square, Triangle, Square, Circle, Circle, Circle, Triangle, Circle.

Thanks to Revolution readers William Ford and Robbie Blazer!