During the last year in school we needed to do a practise exam project.

I went on and decided to control a 'clay-pigeon-thrower' mounted on
an elevator on old telco service truck using FreeBSD and a PCI-based
digital I/O card from AdLink.
The thrower device spins around and can shoot out "clay pigeons" at
different angels and heights.
Good for practising shooting on!

This resulted in a FreeBSD kernel mode driver for the AdLink I/O card
aswell as an X11 GTK application to control the thrower.

It's been in service since 2001 and still is as of June, 2009.
More info at http://www.jaktservice.com

Pictures of the thrower in action are available at:
http://www.jaktservice.com/lerduveskytte.html