Backing up Time Machine

Just spotted a potentially useful how-to about backing up the contents on your Time Machine hard disk to another, so that the internal Time Machine disk can still be used for remote backup of laptops etc. Kudos to MacFixIt for publishing this! :)

http://www.macfixit.com/article.php?story=20080829123830927

And here's the full article details copied verbatim for convenience:

How-To: Migrate Time Machine to a new drive.

Users may wish to change their hard drive configurations for convenience in workflow, adding a new drive, or just for the sake of changing things up. In many cases, users may wish to migrate their Time Machine backups to a new, larger drive, but Apple does not provide a good way to do this.

In order to change the Time Machine database over to a new drive, users cannot just copy the files manually, but instead must use a cloning software package to mirror the current TM drive over to the new one. The procedure is very straightforward, as follows:

Obtain a version of Carbon Copy Cloner or SuperDuper cloning software packages. (NOTE: It may be possible to use Disk Utility's "Restore" function for this, but these software packages have been known to work well for cloning drives.)
Turn OFF Time Machine and deselect the backup drive in Time Machine's preferences.
Connect the new drive and ensure it is mounted and available on the Desktop (formatting with Disk Utility does not matter, unless the drive cannot be accessed).
In the cloning software, select the current Time Machine drive as the source, and clone it directly to the newly mounted drive. This might take a while, depending on the amount of data on the drive and the connection speed.
For convenience, change the name of the old drive and then ensure the new drive has the same name as the old drive (ie, if the old drive was named "My Backups", ensure the new drive has that name). The cloning software should take care of this. Temporarily unmount (eject) the old drive as a safeguard to ensure it is not accessed by the system.
With the new drive mounted, open the Time Machine preferences and select the new, cloned drive. Then ensure everything is working by manually starting a backup instance, and invoke Time Machine to ensure old backups are accessible.
When everything checks out, mount the old drive and use Disk Utility to erase or partition it as is desired.