I agree completely that a proper backup has to be on a separate media. I don't think anyone suggested here that backups be done to just another partition (although there probably are some benefits to that).

On my own systems, I don't want to backup most of the stuff, it's already "backed up" on the original CDs. e.g. Windows and lots of installed apps.

The advantage to "backup" that I was trying to describe is that you can isolate the critical stuff into a smaller, more manageable area. I have stuff that changes daily, I don't want to wrestle with a 20 or 80GB disk, so the critical, dynamic stuff is all by itself on its own partition. Works for me!

E.g. my laptop comes home with me each Friday with a week's worth of whatever on it. At home I plug it into the LAN and run a homegrown program that scans/compares laptop and desktop systems and automatically updates both systems, but all I care about is a 5GB partition, so it takes a 1/2 hr instead of all night.

Seems like a simple matter of improved organization to me.