BACKING UP TO YOUR IDISK

The iDisk makes a useful storage area for backups, so that in the event of a total disaster like your house burning down you still have your essential files. You can access your iDisk by mounting it on the Desktop (command-shift-i) and back up to that, or you could use 'iDisk syncing'which turns on a 'local copy of your iDisk on your Desktop which is synced in the background to the server. It's not advisable to use the 'local copy' as your main folders: if a sync goes wrong you could lose files.

Personally I dislike iDisk syncing because it is so extremely slow: but if you are prepared to leave your computer(s) on all the time it should work OK. The best way to go about things is to use a 'proper' backup program which can backup incrementally to the mounted iDisk: Intego's Personal Backup ($49) and Softobe's FoldersSynchronizer ($40) (both Tiger or Leopard) can do this - either backing up or syncing: they save in Finder format so any restoration is simple; they can exclude certain files or folders if required; they backup incrementally, replacing only changed files (note that they do not retain earlier versions of changed files - only Time Machine does that, and only to an external hard disk). They can backup/sync more than one folder to the equivalent on the destination, and can schedule syncs if required.

You could either do a backup/sync to the mounted iDisk (which takes quite a long time)  - not all programs will do this but these two will - or to the 'local copy' when you have iDisk syncing turned on - this is much quicker and then the contents of the local copy will be (very slowly) synced to the iDisk - you could leave this to run overnight, and if another computer is involved then its local copy will also be synced.

A new and interesting development is a program called 'Twin' (requires Leopard). This incrementally backs up one selected folder per backup, connecting directly to the iDisk so you don't have to mount it and involve the Finder - a huge advantage (I've had the Finder hang when connecting and mess up the entire computer requiring a forced restart). You will either have to choose, say, your Documents folder (you can exclude specified files) and then make another backup plan if you want to backup another folder; I set up a folder on my hard disk and used Personal Backup to back up to that from several folders, then used Twin to back up to the iDisk.

It works well: noticeably faster than using the Finder connection, and also while making a large initial backup the connection dropped for a few minutes and it survived that, just recommencing when the connection came back. The only potential problem is that it backs up into a lot of zipped files, splitting larger original files between them. While in theory you could unzip all these files again manually it would be very difficult (I have almost 800) and I don't know that you would be able to rejoin split files. So you need Twin to restore.

Since if you also have local backups you probably only need the online one if the house burns down, and over a few years you never know if a small firm like this will go out of business, you should zip a copy of Twin together with your serial number and upload that to your iDisk, so that in the event of a disaster you would be able to download that first. It's important to do this, otherwise you could find yourself unable to do a restoration.

On the basis of my experience so far I would recommend this program; it is perhaps a little expensive at €49 (around $69/£42).