For the really cheap solution, you can just get a mini-itx atom board, mini-itx case, and a few external usb enclosures for the hard drives. It's what I have a

For the really cheap solution, you can just get a mini-itx atom board, mini-itx case, and a few external usb enclosures for the hard drives. It's what I have at home, running opensolaris on Xen. I mapped the usb drives natively to opensolaris so I'm not creating disk images on each. It's still fast enough to stream movies on. Not counting the external hard drives, it'll probably cost you around $200 for the PC, and about $125 per terabyte (usually around $25 per usb enclosure). One of the reasons I used Xen is because OpenSolaris still lacks proper network drivers for just about all the network cards I own. It also had issues with my external usb drives, so it was just easier getting linux to handle the hardware interfaces to opensolaris. I use it as timemachine backups for my macs & media storage... but on a cheap budget.