For what it's worth about two years ago:
I had a cron job setup to do the following:
2:00AM - activate my CD-RW and wipe the RW disc clean (kept the disc in at all times)
2:01AM - erase old timestamp file
2:02AM - touch a new file called timestamp and echo my uptime and current date/time into the file
2:03AM - Create an iso image of my home directory
3:00AM - burn the iso image
4:00AM - erase the old iso image
It worked flawless every night for about 6 months, I effed something up on my system and said, "Hmm sit here and fix it for hours, or just reinstall and copy my backup CD...brilliance..."
Formatted - Pulled the CD out, dropped it, scratched it and kicked myself in the ass.