HotHardware.com posted a High Capacity, Low Budget Media Server Build Guide
A quote from the article:
>> A High Capacity, Low Budget Media Server Build Guide
In this post, we'll show you a few select options for putting together an affordable media server computer for under $300 that can store all of your media in one central location and is small enough to fit just about anywhere in your house. This build guide is for a server that will probably be running headless (without a monitor) and not for an HTPC, although you can probably turn it into one by simply dropping in a discrete video card.
>> A High Capacity, Low Budget Media Server Build Guide