Oh just noticed Live drive has 5 GB of free storage space with Windows
Live Mesh.
That can sync a folder, not looked into it, but "it may work with a Calibre library" and keep it synced
On the other hand it may mess it up :S
Edit:
Looks like it will sync between 2 computers, and the livedrive space.
Also let you login to you synced folder from another PC, so you can work on your files etc
Anyone used this
http://explore.live.com/windows-live...programs?T1=t4