These codes are entered by going to Dexter's Diner and selecting the 'Codes' option. Each of the characters other than the PK Droid and the Gonk Droid has a special ability.

Unlock Invincibility - 4PR28U

Unlock Boba Fett - LA811Y

Unlock Jango Fett - PL47NH

Unlock Darth Maul - H35TUX

Unlock Darth Sidious - A32CAM

Unlock Bobba Fett - LA811Y

Unlock Count Dooku - 14PGMN

Unlock Droideka - DH382U

Unlock Geonosian - 19D7NB

Unlock Ki-Adi Hundi - DP55MV

Unlock Kit Fisto - CBR954

Unlock Minikit Detector - LD116B

Unlock Padme - 92UJ7D

Unlock Princess Leia - BEQ82H

Unlock Rebel Trooper - L54YUK

Unlock Royal Guard - PP43JX

Unlock Shaak Ti - EUW862

Unlock Luminara Unduli - A725X4

Unlock General Greivous - SF321Y

Unlock General Greivous' Droid - ZTY392

Unlock Mace Windu (Episode 3) - MS952L

Unlock Super Battle Droid - XZNR21

Unlock Battle Droid - 987UYR

Unlock Battle Droid (Commander) - EN11K5

Unlock Battle Droid (Geonosis) - LK42U6

Unlock Battle Droid (Security) - KF999A

Unlock Clone (Episode III Pilot) - BHU72T

Unlock Clone (Episode III Swamp) - N3T6P8

Unlock Clone (Episode III Walker) - RS6E25

Unlock Clone (Episode III) - ER33JN

Unlock Disquised Clone - VR832U

Unlock Gonk Droid - U63B2A

Unlock PK Droid - R840JU