These all activate in your start menu. They're not really cheats, just sort of fun bonus things to do.

extra toggle 30k
fertilizer 10k (when you ride an animal and press a button, they "drop" brown studs which do nothing)
disguise 10k
daisy chains 5k
chewbacca carying c3po 10k
tow death star 5k

tractor beam 40k
super zapper 15k

Note that scores are *cumulative*!! So if you have 4 and 10 on, you get x40 :)
score x4 - 6m
score x6 - 12m
score x10 - 30k

super ewok catapult - 60k

super blasers 30k
fast force 25k
super lightsabers 26k
invincibility 900k

self destruct 20k
fast build 40k
minikit detector 500k

Lego Star Wars 2 Walkthrough