Uncomfortable plot summaries
The premise: Take the plot of a movie, book or TV show and reword it to totally misrepresent the original work. This is similar to the idea of trailer recuts I posted a while back.
The results: Hilarity. Be sure to read the comments as well. While a lot of the people seem to be missing the point, there are some gems buried in the comments.
As for my own untitled work: Boy moves to a magical underwater city, becomes a great leader, lives forever.