All my important (work) data is on a Unix based CVS server which is backed up nightly with copies of the tapes being stored off-site. I have one current project which has yet to be added to the Unix repository (I use a local CVS repository) which I FTP to a backup folder on our Unix box when I am in the office. Ditto for my email messages (I have mailboxes going back to 1997 for some reason). Hence, if my laptop goes titsup.com then I might lose a few hours work at most. Thnaks to the joys of ADSL/VPN, even when at home I make sure I copy my local CVS store to a central server just in case my laptop gets dropped/stolen. I would spend more time re-installing my local apps (Visual Studio, etc.) then I would recovering lost code.
My biggest worry would be losing all my MP3s! I am considering investing in a portable backup drive for this reason (my boss wouldn't be too pleased if I uploaded 10GB of MP3s onto one of our central servers!).
When I am king, you will be first against the wall.
My data's lost? AAAAAAAAAAaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaahhhhhh!
Oddly enough, this happened to me recently, after i accidentally left out a check for an empty path in a recursive delete routine. Those lost were small among the ranks of files, but will be missed just the same.