[Adam] made a remote camera trigger that uses a laser. He had to install CHDK on his camera, which we’ve featured in a how-to, in order for it to work. CHDK allowed for a remote shutter trigger through the USB port. The laser bounces off a mirror and onto the photoresisitor hooked up to an Arduino. When the beam is broken, the Arduino sets off the trigger. He also plans to use the trigger to tweet over ethernet. Embedded is a video demonstrating its functionality.