Subscribers to Apple's .Mac service (at $100 per year) currently get up to 1 GB of iDisk storage space, with the option to increase to 2 GB for $50 per year or 4 GB for $100 per year. Apple's Backup application, and most other backup utilities, can use an iDisk as a backup destination. Unfortunately, even 2 GB is far too little space to meet most users' needs, and transfer speeds to the .Mac servers are often quite slow, even for users with broadband connections. In addition, you cannot make a bootable backup onto an iDisk. For these reasons, your iDisk is not an ideal backup destination.
On the other hand, for casual (manual or automatic) backups of just a few files between regularly scheduled archives, an iDisk does make a convenientand inherently off-sitedestination.