Well, I had a bit of a snafu recently. I've been working hard on Black Hat Magick volume 2: Tango & Cache when -- if thour't following my Twitter feed @kytsune -- I discovered that I'd somehow lost chapter 15. Totally missing. Not present in any of my online backups.
The worst part of this is that I don't have incremental backups that last more than a month now. I used to run an SVN server that would keep my files in revisions so that I could roll them back if I were to totally catastrophically mess something up.
Does anyone have an incremental or revision backup service they've found useful?
Of course, part of my problem is that I also encrypt my entire manuscript (in one volume) which I figure I'd have to give up for incremental backups. Not that I'm paranoid about someone taking my story, it's more about keeping data safely in the cloud.