It has no hard drive and boots using PXE from my server, then mounts its filesystem over NFS. It runs Debian Linux, xorg, XFCE4, Metacity and Firefox. The button on the left of the panel at the bottom of the screen pops up a screen keyboard.
Currently I’m a bit concerned about the amount of heat that builds up from the PSU (reaches 75°C after a while), an external PSU might be required. Also it tends to run out of RAM when viewing stuff on google video (no swap, no hard drive).
Update: I’ve done some work on the insides, see here. It still looks the same on the outside.
Further update: I’ve switched from the above described software to running KDE. More details here.