The Raq is a very small rack-mounted server made by Cobalt Networks. It is a bright purple, and takes up 1U of rack space, which means that you can fit about 80 in to a standard comms rack.

The Raq is at it's fourth revision now, and the latest model - the Raq4 - has a 450Mhz processor, up to 512Mb of RAM, dual hard drives, dual 10/100 ethernet, and a fancy LCD display on the front to configure it with. All in 1U. Clever, eh? Did I mention it ran Linux 2.2?