Well how elaborate do you want to go?
Here are a few my friends have done.
1. Shut out the power to the the friends room at night (my friends did this to an entire girls dorm at a small private college), sneak into rooms while girls are sleeping, turn on all lights and turn volume all the way up on all the tv's and radios, Turn power back on....
2. Remove all light bulbs out of entire house/dorm room.
3. Remove everything from room, replace with sand, and a inflatable pool, beach chairs, inflatable palm tree.
4. Release live Canada Goose inside room, while everyone is in the room. (this could probably constitute, animal abuse so I dont' really recommend it, but it was da@n funny).