Save your final paper in many places, that way you don't accidentially delete something and have to rewrite the ENTIRE paper in 2 hours using a finger with a hole in it.
*falls over dead*
Documentation - redundancy redundancy redundancy!
I have 4 * 350MB sata HD configured in raid 0 + 2 spare 400 MBHD + 3 USB HD + many backups in DVD...
I have a little Linux based NAS server just bigger than a pack of cards with 2 x 300Mb discs in RAID 1. Problem is that the discs attach to the server by USB and so don't spin down when idle, which is noisy. So the setup lives in a cardboard box under my desk and only comes out once in a while. Far from ideal.
That's a real bummer. I've seen it before and sympathise with you.
Somehow "the computer ate my essay" just doesn't sound right.