A parlor game my sister learned at summer camp about ten years ago.
The game is played with a group of about 2-6 people, a sheet of paper and some pens. A random person is given the piece of paper, and write about a paragraph of random storyline. When that person is finished, they fold over the piece of paper so only the last line is showing. Often this line is half completed. The person who recieves the paper then continues the story, guessing from the fragment they have what the story is about.
By the time the story is over, everyone has contributed to it, usually several times. And usually the story has careened wildly amonst several characters involved in sexual or scatological themes. although this depends on the maturity and sobriety of the participants.
When my sister played this game at camp so many years ago, it tended to focus around the camp counsellors and certain campers. As me and my sister played it over years in our hours of boredom, we tended to focus on a series of stories about how Phil Collins, Sting and Axl Rose were at a ranch in Utah run by Danny Ainge and Thurston Moore, where they had been banished by the Queen of England for art rock tendancies.
Once you have this game going, you can really do some creative things with it. Or you can use it for cheap laughs.