I have several PC's on the network here at home, but we really don't have the space for them. It's also not very energy efficient. I am considering getting a NAS system. NAS stands for Network Attached Storage. This works very much as a dedicated storage server.
The one that I'm most interested in is the LaCie Ethernet Disk mini, which is available from Newegg for $181.99. For less than $200, this is quite a piece of technology. It includes an SMB (Server Message Block) server, an iTunes server, an AFP server (great for Amy's Powerbook), an FTP Server and others. It contains an 500GB hard drive, which is sufficient to back up our notebooks and other PC's and contain a share iTunes library available to any PC on our network. This will contain every CD and our favorite DVD's. The great thing about this particular NAS device is that it is expandable. It has a USB2 port to which you can attach external USB drives (of which I have several) that will enable us to have a terabyte of data.