Here's what I want to do.

I want to install an OS and an application or two on the puter and then burn the image to a DVD. I want to run some tests, screw around, break things, and then reinstall the original image from the DVD so I end up with exactly the same environment that I started with.

I'm looking at the Sony DRU-510A DVD burner and PowerQuest Drive Image 7 software.

Am I cool?

I think you'd be better off with multiple partitions on the same hard drive, or using two hard drives.
If you hose one partition, you can use safe mode or a diskette to get to a good partition or switch drives.

Cool, I'll look at Ghost too.

Part of the deal is I want to have a number of DVDs, some with Win2k, others with XP Pro and Win98, and I want to be able to restore the images at will with as little BS as possible. I figured multiple hard disks would be too much of a PITA.

A friend of mine does development in a number of environments. What he did was to get a removable drive chassis in his tower and then just have 4 drive modules with 4 different OSes. He would configure each OS and then Ghost that install. This way he can switch between operating systems quickly but each one is a clean setup (no dual booting, multiple partitions or things like that). If he hoses one he just restores it from the ghosted images he keeps on a 5th fixed internal HD for just that purpose.

With the prices of drives today this is not too expensive since you really don't need a large drive for development/testing purposes.