After reading our Light Graffiti post, Neatorama reader tagg told us about this awesome lightwriting video made by lichtfaktor called Star Wars vs Star Trek: Hit play or go to http://www.skycast.com/video/watch/-8109178600655663537/ [Skycast] - Thanks tagg!
To do animation you just keep taking pictures, hence why in the commercials you can actually see the massive amount of time that goes by as morning arrives at the end.