Network Attached Storage on a Budget?

Full'o'MP3 asks: "Wondering what to do with all those (formerly huge) hard disks on the shelves? Well, so am I. After looking at all sorts of USB enclosures, I remembered that, a long while ago, I saw a description/review/whatever of a small board (around 3" by 4") that essentially had an Ethernet interface on one end, a microcontroller in the middle and an IDE bus on the other end. It was designed only for that purpose, could not even format the hard disks on its own and only supported SMB without any access control, but by golly, I'm looking for about a dozen (or about 1 per 4 disks). Slap them inside old PC cases, fill them with hard disks, and you have a very simple, cheap file server for home or school. I've looked at a lot of embedded Linux and commercial storage stuff, but they are all overkill and require brand new hardware. Anyone have any pointers for this? (Butchering old laptops, iPAQs or similar stuff won't cut it...)" Readers may remember this thread from early May about doing something similar with new hardware. Since this is the "budget version" of the similar question, I felt it was deserving of its own post. How hard would such a device be to build fom old computer parts and hard disks? Details on cheap electronics (like the submittor-mentioned device) that would make this easier would be appreciated.