I'm the administrator of this wonderful (okay, I'm biased) computer lab built from barebone parts and open source software back in 2002-2003. As a private school, GHCA would not have been able to afford a typical Microsoft or Apple lab. However, with Linux we were able to get the most modern hardware at the time. Even better yet, that hardware is still more than fast enough even though it is 5 years old, thanks to Linux!
I personally teach Computer Programming, Computer Technology, Research and Presentation, and Microcontrollers. I share the lab with other teachers who teach various computer skills classes and also integrate technology into the classroom. We also have a Robotics and Yearbook club. Details about our computer science curriculum can be found at http://www.ghca.com/computers.
Future goals - replace CRT with LCD monitors, and replace the cases. I want to build a slim-line "console" to house the motherboards, drives, etc. and thus free up a lot of desk space. Once I have time and funding.....
Interesting side-note - I use the 21 computers in the computer lab as a large cluster for compiling software (using distcc). This allows me to build software via Gentoo that is customized to our hardware, which can often result in enhanced performance. Our server acts as a central repository of built binary packages so that once the programs are built using the "super computer" cluster, they can be quickly installed on any machine! You can watch the process HERE.
One last side note - we have a blast playing 20-way BZFLAG when the opportunity arises :-)