Enter all these on the main menu.
All power moves:press L,L,R,R,L,R,L,R
Unlimited use of Batlauncher:press Y,X,Y,X,L,R,L,R
Make Caped Crusader invincible:press L,R,X,L,R,Y,L
99 of every item:enter L,R,Y,Y
Unlock all FMV movies:enter L,L,X,X,Y,X,L,R
Unlimited Batarangs:enter L,R,Y,X
Unlimitted supply of handcuffs:enterX,Y,X,Y,L,R,R,L,L