UPDATE: Blinkybug Kits, which include all the parts to make 4 bugs, are now available on Make Magazine's online Maker Store
are small, eletro-mechanical insects that respond to stimulus such as movement, vibration, and air currents by blinking their LED eyes. They're incredibly simple, yet have a certain lifelike quality.
I've been making variations of these for a while now, and showing others how to make them at museums, fairs, workshops, etc. It isn't rocket science, but there's some tricky soldering involved, and they usually take a person at least an hour to put together for the first time.
I wanted to come up with a solder-free version for the workshop I was organizing for the http://www.makerfaire.com/
2007 Maker Faire], which took place May 19 + 20 in San Mateo, CA. So after a bit of experimenting, I came up with this simpler design.