Shuttle has begun offering two compact PCs with the Linux operating system, branded symbolically LinuXPC's. The first one, named Shuttle LinuXPC SD3002W, uses SUSE Linux Enterprise Desktop 10 SP1, and the Shuttle LinuXPC SD3002Q comes with openSUSE Operating System.
Both of these models can be outfitted with Intel processors, up to 2GB of 667MHz DDR2 memory and they come with a PCI-Express x16 and PCI slot and various storage configurations. Both models feature Intel GMA 950, six USB 2.0 ports, 8-channel audio, Firewire and Gigabit LAN. You can order it with a DVI interface if you want to connect it to a large TFT monitor. Both models come in two color options, silver and black.
Shuttle is offering the Linux based machines in Germany since in September, but for now LinuXPC's are available in the U.K. and Austria. Shuttle's recommended price for basic configurations are €436/£313 for the LinuXPC SD3002W, and €402/£288 for the LinuXPC SD300Q2.
You can check both of them out here.