Originally Posted by chainring
Sign up for a Dropbox account (free for 2GB), stick your calibre library in there and don't worry about backups in the future. Dropbox keeps revisions of everything.
Please use my referral link if you like the Dropbox idea.
I would TOTALLY take you up on this and get you some extra GB, but I'm already a Dropbox convert and user. Love using it to keep stuff synced between my home computer, my work computer, my iPad and my iPhone.