Is there a way to use extra space on computers as a distributed backup system? I'm thinking that using the extra space on the systems in my network would add a lot of storage to the available pool, even if I use a lot of the nodes for redundancy.
---Edit---
I am thinking something along the lines of a program that can be installed as a background process, and can be configured to announce that it has X MB of space available to whatever the server is. So, you add a new node by installing and dropping in a config, and on the server end, it adds another redundant copy of some data and/or X amount of storage to the pool.