Warning: Do not do all of them in one class.
1. Try to develop psychic powers, then use 'em.
2. Inflate a beachball and throw it around the room.
3. Sing Show Tunes.
4. Make loud animal noises then deny doing it.
5. Think of new pick lines. See if they work.
6. Pretend you're flying a jet fighter in the Gulf War.
7. Churn some butter.
8. Conceive a brand new language.
9. Walls made of brick. Count 'em.
10. Plot revenge against someone.
11. Think of nicknames for everyone you know.
12. See how long you can hold your breath.
13. Take your pants off and give them to the professor.
14. Chew on your arm until someone notices.
15. Change seats every three minutes.
16. Think of ways to cheat at Trivial Pursuit.
18. Run across the room, tag someone and say "You're it.".
19. Announce to the class that you are God and that you're angry.
20. Think of five new ways to use your shoes.
21. Start a wave.
22. Walk around the room begging for spare change.
23. Roast marshmellows.
24. Practice phrasing your answers in the form of a question.
25. Crawl around the room humming the music from Mission Impossible.
26. Take apart your desk.
27. Pretend to communicate with your home planet.
28. Play rock-paper-scissors with yourself. Accuse your left hand of cheating.
29. Do a quick tapdance routine.
30. Try bird-watching.
31. Walk up the aisle yelling, "Popcorn! Hot popcorn here!".
32. Throw your backpack at someone.
33. Run to the window, then say, "Sorry, I thought I saw the Bat-signal".
34. Ask the person in front of you to marry you.
35. Start laughing really hard and say, "Oh, now I get it.".
36. Make a sundial.
37. Give yourself a new identity.
38. Write a screenplay about a diabetic Swedish girl who can't swim.
39. Dig an escape tunnel.
40. Announce your candidacy for President.