Secret Ending:
Make sure you have controllers plugged into slot 1 and slot 4. Right before the final fight with Darth Malak, but before you open the door, press Y+R+L on both controllers.

Funny Voices:
Make sure you have controllers plugged into slot 1 and slot 4. Press White and Black on controller 4 to raise and lower the pitch of voices in the game.

Instant Dark Jedi:
*When you find the stowaway on the Ebon Hawk, tell them to "Get out of here!" You will move toward the dark side. Quickly talk to them again and tell them to get out again. You can repeat this as many times as you like.

*On Manaan, go to the Republic Embassy and go to the computer next to where they are holding Largo. Make sure you have at least one computer spike but no more than seven. After hacking into the computer, select "Kill the prisoner.' Since you do not have enough spikes, you won't kill anyone, but you still recieve dark points. Just keep clicking this option to go Dark.

*You have to poison the shark in order for this to work. On Manaan when you get the Star Map and go back to the surface, the Republic Rep. will ask you how it went. Tell him you poisoned the water and go through the conversation. Then he will ask you to keep quiet about the station under the water; reply "For a bribe I can do that." You will get Darkside points. Keep clicking on him after the first conversation you can continue to get dark points.

Keep the Sith Armor and the Sand People Robes:
Simply equip either of these items to one of your characters right before you are forced to give them up. Proceed as normal.

Secret Jedi Robes:
When you go up against Darth Malak, you're gonna want some good robes for a strong defense. On the second deck of the Starforge, among the armada of dark jedi, you'll run into a bunch of turrets. Don't blow them up, but go to the nearby computer room to shut them down. Once you get past the dark jedi and deactivate the turrets, access the "create custom robes" option on the console. The robes differ whether you're on the light or dark side, but the protection is great either way.

Two Baccas blades:
First you must make sure Zaalbar doesn't have a weapon equipped. Then go to the Star Forge System and join Bastilla after you fight her atop the Great Temple. When you return to the Ebon Hawk, you will tell everybody of what happened, and after Carth runs away tell Mission you're going to kill her. Zaalbar and Mission will attack you. Zaalbar will be using Baccas Blade even though it's still in your inventory. After you kill them check Zaalbars remains, there should be a Baccas Blade inside.

Sith encryption puzzle - Manaan Republic Enclave:

Additive = 22
Subtractive = 18
Multiplication = 64
Divisive = 2
Exponetial = 6
Logarithmic = 7

Save Your Spikes:
On the Star Forge, do not waste Computer Spikes on custom jedi robes - you will need the spikes to destroy the Forge Droinds later in the game. (You get spikes, but only after you destroy a few Droinds. Saving the spikes makes the process quicker, and you can save FP and Life saving items for Malak.)

Return Bastila to the Light Side:
When you reach the Star Forge and confront Bastila, make sure before and after each battle to choose the following coversation choices in order to bring her back to the light...

"I'll never give up on you, Bastilia.."
"I'm as strong in the light as I ever was.."
"Malak will never let you.."
"You're dooming yourself to.."
"Then strike me down.."
"You are not evil, Bastilia.."
"Now you can see the dark side.."
"There's no need for me to.."
"You can reject the dark side.."
"I was redeemed, Bastilia.."
"You did protect me.."
"Help us defeat.."
"I trust you to.."
"You won't, Bastilia.."
"You could use your.."