Good methods of annoying your roommate:

1. Switch the sheets on your beds while your roommate is in class.
2. Steal a fishtank. Fill it with beer and dump sardines in it. Talk to them.
3. Learn to levitate. While your roommate is looking away, float up out of your seat. When s/he turns to look, fall back down and grin.
4. Move your roommate's personal effects around. Start subtlely. Gradually work up to big things, and eventually glue everything s/he owns to the ceiling.
5. Walk and talk backwards.
6. Spend all your money on Jolt Cola. Drink it all. Stack the cans in the middle of your room. Number them.
7. Get a computer. Leave it on when you are not using it. Turn it off when you are.
8. Fake a heart attack. When your roommate gets the paramedics to come, pretend nothing happened.
9. Eat glass.
10. Smoke ballpoint pens.
11. Smile. All the time.
12. Hide a bunch of potato chips and Ho Hos in the bottom of a trash can. When you get hungry, root around in the trash. Find the food, and eat it. If your roommate empties the trash before you get hungry, demand that they reimburse you.
13. Leave a declaration of war on your roommate's desk. Include a list of grievances.
14. Shoot rubber bands at your roommate while their back is turned, and then look away quickly.
15. Hide your underwear and socks in your roommate's closet. Accuse them of stealing it.
16. Whenever your roommate walks in, wait one minute and then stand up. Announce that you are going to take a shower. Do so. Keep this up for three weeks.
17. Array thirteen toothbrushes of different colors on your dresser. Refuse to discuss them.
18. Shave one eyebrow.
19. Put your mattress underneath your bed. Sleep down under there and pile your dirty clothes on the empty bedframe. If your roommate comments, mutter "Gotta save space," twenty times while twitching violently.
20. Shelve all your books with the spines facing the wall. Complain loudly that you can never find the book that you want.
21. Always flush the toilet three times.
22. Listen to radio static.