The CTL 2go PC Nettop baseline model features a Intel DG945GCLF motherboard with a Atom 230 1.6GHz processor, 1GB Kingston DDR2 memory, integrated Intel GMA 950 graphics, support for one HDD and one optical drive, six USB 2.0 ports and Ethernet.
The Essential Plus Edition costs $199, it adds in Ubuntu and a 80GB 720RPM HDD but cuts the memory to 512MB. Add in a cheap LCD display and you got yourself a pretty cheap low-power machine for office work or web browsing.
If you want Windows XP you can get the $299 Essential Performance Edition which features Windows XP Home Edition, 160GB HDD and 1GB memory.