can i suggest a backup for the backup? i've used an external hd for backup before but it also did get corrupt. so now i have a backup for the backup.
Whilst fool-proof, a little unnecessary? Surely if your backup gets corrupt, you just backup from the Original again?
Saying that, you'd have to be pretty unlucky for both the original and backup to corrupt at the same time, which did happen to me recently with my iTunes drive.