The Internet-submitted films are too amusing, too:
Chocolate Love: A man finds love in a parking lot (teehee).
Chick Fight may be the best of them all (and big chunks of it were used in the final movie).
The Balance. I don't really get the title, but I love the music and the story in it.
Last one I'll link, because I could link them all! zBabes from Beyond the Grave: Axe can even help you with zombies!
The production quality on some of these fan-made ones are just amazing (Chick Fight and zBabes, for example).