How to Build a laser tripwire that can trigger anything out of a photoresistor

This video, incredibly short for it's massive content, will teach you how to make a laser tripwire that, combined with a photoresistor, can trigger just about any device. You can make traps, alarms, awesome party decorations, and all sorts of other awesome things with this easy-to-make device, provided you have a soldering iron and a local electronics store to buy some parts.