Jeff: Whether you’re running a pair of drives as RAID 0 or just a single drive, any disk failure is catastrophic. Even if you run a pair of drives in a mirrored config that’s still no guarantee of data integrity if something bad happens.
We’ve had data on whole RAID-5 arrays on our hosting platform rendered utterly useless and unrecoverable because the RAID controller on the last few hours before failure began silently flipping bits, dropping data here, there and everywhere before we detected that it was in real trouble. When it did eventually fail, the data was useless. This happened three times before the manufacturer admitted that there was a problem with a batch of cards.
Fortunately we have a rolling off-site backup that goes back 28 days and we were back up and running at a point just before the wierdness began.
Even if it is just a desktop, if the data is important then good source control, backup procedures and disaster recovery/business continuity practices are imperative no matter how many disks and mirrors you might have. If you have to go sending disks off to data recovery companies then it serves you damn well right for being sloppy with regard to DR/business continuity planning.