Here's another novel use of an Arduino board, a laser pointer, and a Linux machine - a system that tweets when a laser beam is broken, and also triggers a webcam on the host PC to record what just happened. Although it sounds complex, it can be done with the included code and a Linux machine. Here it is in action:
Not bad at all for a prototype, there could be a lot of possibilities with such a system. The use of the cassette box as an Arduino stand is neat as well. Remember when working with laser pointers to take care about looking into the beam or reflecting it on others.