Press backspace during a game then:

Type	To cause
oldcode	Displays "debug 1". Typing again displays "debug 2".
happy	Weapon 3 has more power and displays "Open you heart". Typing again returns it to normal power and displays "Excellent meditating!".
from above	Changes camera to directly above player and displays "Get up on it". Typing it again moves the camera directly behind the player and displays "Get down ag'in".
naughty naughty	Moves the camera directly behind the player and displays "Behold my neck-spike", typing again and moves the camera back to normal and displays "Blort!".
perf	Turns wireframe display on and off
60fps	Displays "60". Typing again displays "30". It changes the maximum frames per second.
but i feel so good	Force power bar colour is changed to red and displays "You're the guy with the Force". Typing again changes it back and displays "Play nice".
perfection	The push force power now kills and displays "Deadly force authorized", typing again returns force power to normal and displays "Nobody's perfect".
slowmo	Activates slow-motion, displays "Super slowmo mode", typing again returns it to normal and displays "Normal mode".
beyond cinema	Puts it into widescreen and displays "letter-box", typing again returns it to normal and displays "Back to 'ol pan-n-scan".
turtables	Turns off cheats codes and displays "The tables have turned". Typing again displays "It was just a dream... OR WAS IT?!". You will have to exit the game and restart to reactivate cheat codes.
i like to cheat	Gives all the weapons and adds a load of ammo and displays "You are now the biggest cheater in the world".
give me life	Sets health to 100, even if it was already higher and displays "Rock on"
heal it up	Sets health to 100, even if it was already higher and displays "Rock on"
where is gurshick	Runs credits
brenando	Displays "Tech Bonus!".
rex	Red lines around menu boxes and displays "Feel the power of REX".
iamqueen	Play as Qeen Amidala
iampanaka	Play as Captain Panaka
iamquigon	Play as Qui-Gon Jinn
iamobi	Play as Obi-Wan Kenobi
i rule the world	Displays "You da Man".
i really stick	Sets skill level to easy and displays "Skill Level Set to Weenie".
fpm	Displays frames per second on screen, typing again removes it.
donttttt	Kills player and displays "That's what you get for saying that".
rrrrright	Kills player and displays "That's what you get for saying that".
kill me now	Kills player and displays "DON'T DO IT MAN!!!!"