With a few parts from around-the-office components and a quick trip
to Radio Shack, you can create a device that allows you to listen in
to conversations on the INSIDE of windows that you point the laser
at. Previously, the realm of spies, now in the reach of soldering-
capable nerds everywhere.
http://www.metacafe.com/fplayer/767822/laserespionagemicrophonehowto.swf