OpenDesktop.org offers the Open-PC, an open computer that works with free drivers and no proprietary software is needed. It is powered by the usuall Intel Atom 330 1.66GHz dual core processor, 3GB of RAM, 160GB hard drive and GMA 950 graphics.
The Open-PC uses Mini-ITX case and measures 345mm x 100mm x 425mm. It runs Linux/KDE-based OS. THe price is Euro 359 including Euro 10 donation to the KDR project.