CrunchDeals: HP MediaSmart home server for $299
The machine itself is outfitted with a 64-bit AMD Sempron CPU, 512MB of RAM, 500GB 7200rpm hard drive (with three available expansion drive bays for adding extra hard drives), and the Windows Home Server operating system.
This deal is available online only and lasts until November 29th.
HP EX470 MediaSmart Server [OfficeMax via dealnews]