The simplest and cheapest digital track timer ever !!!

I might just have to attempt this! Make is a great site...always something interesting on there!

That is pretty nifty, very DIY. Fair warning about those light sensors though, I found them to be very picky when I tried to make my own sensor line several years ago. It's a case where you'll need a truss over the track with lights shining down on the track. Otherwise the variance in ambient light will play havoc with your sensor.

I think IR or other beam sensors are far more reliable but probably need more circuits or something.

I dig the use of the stop watch though, nice pretty numbers at least.