Hi, everyone. I stumbled upon http://video.google.com/videoplay?docid=6491441475172785592#" [Broken] I can't quite figure out how it works, so I figured I'd throw it out to you all. I got so far as to come to the conclusion that it has to do with a buildup of static electricity and that, since the setup is symmetrical, the direction of the current is determined early on by random imbalances, and doesn't have to be the same direction each time. Also, I've ruled out the triboelectric effect, because the water is only hitting the bottom of the drum in the beginning, but soon, it's just hitting other water. I say all that just to let you know I took a stab at it before crawling shamelessly to the hive mind.