Pitfall: The Lost Expedition:

Bottomless Canteen Code: 
Hold L1 and R1, and then press LEFT, SQUARE, CIRCLE, DOWN, SQUARE, X, SQUARE, CIRCLE. 

Unlockable Hyper Punch Mode: 
Hold L1 + R1 and press LEFT, RIGHT, CIRCLE, UP, CIRCLE, RIGHT, LEFT

Classic Pitfall Game Mode:
Hold L1 + R1 then press Circle, Circle, Left, Right, Circle, Square, X, Up, Circle

Play as Nicole Mode:
Hold L1 + R1 then press Left, Up, Down, Up, Circle, Up, Up