set his car on fire.
tie his door knob to something in the hall way so he can't open his door.
vaseline on wood floors is good idea
put water on the carpet outside his door.
get a gallon of milk (or half gallon), heat it up then pour it somewhere remote in his room (under his bed against the wall, back of closet, behind dresser) or hell, all of them so when he finds one and cleans it hell still have more milk shit smell in his room.
shampoo under his pillow.
let random animals loose in his room (chickens, pigs, etc etc )
rub insulation all over his bed so its itchy.
does he have any allergies? Use this to your advantage.
hack his myspace/facebook and blog about ******* cawk.
these are just off the top of my head