Backdown is a distributed backup system. Users back up each others' data using their free local and cloud storage (encrypted of course). When disaster strikes, our system recovers a user's data via redundant fragments stored on other users' drives.
Syncing takes place in realtime, and everything is managed via a simple, easy to use client. Users are allocated space based on how much storage they offer to the system. Expansion points can include adjustable redundancy, and a cloud based client.