Came across this contest winner on the Parallax website

http://www.parallax.com/DAQPacAutomotiv ... fault.aspx

Excellent documentation including schematics and board layout here:
http://www.parallax.com/portals/0/downl ... Report.pdf

Amazing what can be done with an $8.00 chip + peripherals

This one is even more insane (R/C autopilot)
http://www.parallax.com/tabid/726/Default.aspx

Couple of cool videos (two R/C planes on same holding pattern run into each other on the first go-around...talk about accuracy!)
http://www.vimeo.com/2599290
http://www.vimeo.com/2477624