My addition to the thread - A toolbox PC. 1.1Ghz CPU, 384mb ram, 12Gb HDD, TV-out card. It has a wireless keyboard and mouse if required but it's main interface is a trackball I bought on eBay from an old Air traffic control tower.

Its used as a karaoke machine as a I didn't own a laptop at the time and it seemed a good use of some bits and pieces I had lying around.