Distributed Data Storage on a LAN?

AgentSmith2 asks: "I have 8 computers at my house on a LAN. I make backups of important files, but not very often. If I could create a virtual RAID by storing data on multiple disks on my network I could protect myself from the most common form on data failure - a disk crash. I am looking for a solution that will let me mount the distributed storage as a shared drive on my Windows and Linux computers. Then when data is written, it is redundantly stored on all the machines that I have designated as my virtual RAID. And if I loose one of the disks that comprise the raid, the image would automatically reconstruct itself when I add a replacement system to the virtual RAID. Basically, I'm looking to emulate the features of hi-end RAIDS, but with multiple PCs instead of multiple disks within a single RAID subsystem. Is there any existing technologies that will let me do this?"