How to: Turn a bowl of water into an $8 audio controller

Sebastian Tomczak is an Australian musician/programmer/video game hacker. This video shows how he turned a laser pointer, a bowl of water, a solar panel and (I'm guessing) a Max/MSP patch into a (nearly) musical instrument. He's developed the concept into the Toriton Plus, with five lasers. It's beautiful, although I get nervous seeing that bowl of water next to a laptop... (Thanks, Steven)