While the HP produced disks are good to have, they're not necessarily better than a home made version as I, and others have suggested.
With my method, your restore disk can be kept up-to-date. When you restore, you just have to download updates from Jan 07 on, rather than having to go back to the SP2 release. You can also add a copy of Office, or any other program into your image (and keep them updated too). You can have your ISP settings in there as well, and any other settings, etc.
Plus if you do the partition idea, then once you've restored & updated your system, you can make another image & keep it for when you restore again.