Very good trick. You can redirect certain Windows folders from their default location to an alternate location.
You may also look at RAID arrays (1,5,10) for redundancy on a hardware level.
Another option, IBackup - Online backup.
You could combine hardware redundancy (RAID) with onsite image based backup (Shadow Protect, Norton Ghost, Acronis, etc) and an online backup to ensure a very high level of disaster tolerance.
EDIT: What Trowa is referring to is imaging, which will not backup customer data. It's a good practice in case the system gets FUBAR, but you'll need to configure a backup schedule to perform incremental or differential backups (images)