This kind of gives a light show effect. Sorta, I mean, it's not exactly a Kanye style light show, but it does throw pretty patterns onto the wall and ceiling and it's dead easy to make. I think I've covered the basics here, but if you get stuck (or you're looking for some other ideas on Dirt Cheap Decorating) go here

http://www.instructables.com/id/Make-A-Light-Show-Well-kinda-Lampshade/