Ninety-nine lives
Enter XNB9FM!Z2? as a password. 

Picture in a picture window
Pause the game, hold R2 and press Circle, Circle, Left, 
Circle, Circle. Enter the code again to return the screen 
to normal. 

Large Rayman demo
Hold L1 + L2 + R1 + R2 after the Ubi-Soft logo. Keep holding 
the buttons until the animation of the brick wall appears. 
Then, hold Start. Release the buttons when the screen turns 
black to see the large Rayman demo.

Full power up with 99 lives
This one is a long trick ... but after awhile, you'll get it.

Press Start, then carefully press in order and 
hold L2 + R1 + L1 + R2.
Release the buttons in this order: L1, L2, R2, and R1. 
Then press and release
Circle. Hold Left + Circle + Square + Triangle. 
Release the buttons in this order: 
Left, Triangle, Square, and Circle. 

If you did this corectly you'll have full power and 99 lives!!!

Another way to do this code is: Press Start, then carefully press in order and
hold L2 + R1 + L1 + R2. Release the buttons in this order: L1, L2, R2, and R1.
Press and release Triangle. Hold Right + Circle + Square + X. Release the
buttons in this order: Right, X, Square, and Circle. ( I like this one
better.)

For NTSC version

Status
Password  
Band Land completed
J5VLFP58VB  
Blue Mountain completed
J5K!ZZC8MD  
Cave of Skop completed
SM!KV7WSXD  
Picture City completed
SX2!ZP58MD  
All cages, all abilities at last level
SD3BKFOOMN 
Last level with 99 lives
942KV3W9XD  

For PAL version

Status
Password  
Band Land, Allegro Presto
!GNSZ36N9X  
Blue Mountain, Twilight Gulch
PJNJF!Q29P  
Blue Mountain, The Hard Rocks
Z?WOZ3QTFP  
Picture City, Pencil Pentathalon
Z8N8P36D6P  
Picture City, Space Mama's Crater
Z8WOZ5QNOZ  
The Cave of Skops, Crystal Palace
VPN8P!646Z  
The Cave of Skops, Eat at Joe's
P1NO7!6NSZ  
The Cave of Skops, Mr Skops' Stalactities
FGN83562SZ 
Candy Chateau
FJSJ!C62OP