We used the freeNAS OS from freeNAS.org to setup and NAS over here at ALB Tech We Fix Computers in Mechanicsville, VA.  Here’s a quick video showing our server (pulled from the junk pile), configuration, and a speed test. We got freeNAS from http://www.freenas.org and burnt a DVD. The OS was then loaded on a 4 gig flash drive. Machine is an intel Xeon with 2 used 500 gig drives and 3 used 250 gig drives. We have a gigabit network, but the server only has a 10/100 NIC. Check it out!