While playing the first level (Battle of Hoth), press and hold 4 + 6 + 8 on the number pad. Hold them for about 5 seconds then cycle thru the veiw modes with TAB until you get the AT-ST.
Level Select
At the level select screen enter this code two letters at a time, holding down the 2 letters for 1 second:
RU NO TT* WI TH XI ZO RS
*NOTE: Type T then T again then continue to the next set of letters which would be WI and type them as usual by holding the 2 letters (WI) down for 1 second and then continueing to the next set.
Level Select
Enter a players name as R Testers ROCK.
Max Challenge Point
When you leave Mos Eisley and enter the Dune Sea, take a 90 degree turn left and go straight. You will see a little square, you will there see that adorable urchin Max (as in "Sam & Max Hit the Road.")