Go to the cantina and talk to the man next to the gifts on the shelf and go to the codes and type in wxx998 to get disguse 4. When you have disguise 4 every body will be wereing a skirt.

Hi,at the mos eisley cantina put these codes to unlock characters(they will be able to buy):
BEN917-Ben kenobi ghost
HLP221-Boba fett
TTT289-Ewok
HHY382-The Emperor
HDY739-TIE Fighter
MMM111-Imperial guard
YZF999-Gamorrean guard
QYA828-TIE Interceptor
UUB319-Lobot
WTY721-Bib Fortuna

Also,when you win the challenge mode you get automatically some characters(some good and rare characters).Here are some and in which chapter you get:

Episode4:
Chapter3:Padme,Anakin boy
C.5:Droideka
C.6:Clone pilot(Episode III)

Episode5:
Chapter1:Ki-Adi-Mundi,Kit Fistp,Luminara,Shaak Ti
Ch2:Three forms of Padme-Battle,Clawed,Geonosis
Ch3:Geonosian
Ch5:Super Battle Droid
Ch6:Queen Amidala,Capt. Panaka,Royal Guard

Episode6:
Chapter1:Disguised Clone,Boba fett boy
Ch2:Jango Fett
Ch3: 3 clones and Commander Cody
Ch4:Wookie,Jar Jar Binks
Ch5:Chancellor Palpatine,Grievous and Grievous bodyguard
Ch6:Mace Windu,Mace Windu(ep.III)

Okay,thats all I know.If I get more,I will submit more.Hope I helped!!:)

Here is some cheats that will work on psp only well, some work on xbox 360 and Wii

Grounding: on tatoiween go to the red place where only villans can force! Chapter 3 episode IV and force it you will get 1,000 studs but you know when it shakes you get 1,000 coin stud keep doing it shake shake

The carrot trick: so when you are on jabba's palace find three carrots around the block of where you have to trun well you don't have too but when you turn on the music # 2 time!!!!!!!!!!!! When you find it there will be three carrots find Hint: one is on the roof in the corner: ok after finding them return to cantina and talk to the guy in the well who works there you find an offer for those three carrots a lego stud fountain, playgrtound and 1 million studs do it, stud fountain is like a home lego syuds fall and stay there. After 5 levels complete there will be like 5 million studs.............!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Get darth vader: beat the emporer

Get the emporer: buy him at the family courtyard