Are the discs grey in color, or do they have a big X (roman numeral 10) on them?
They are grey, so they won't be of any real use to me.
However... SWMBO says she has a set of 10.6 Snow Leopard disks, still sealed in their cellophane wrappers, somewhere around the house. Unfortunately, her style of storage for things like that will just about require a front end loader to start looking for them. That'll be the project for tomorrow, I guess.
The "identify your mac" site you linked to was a bit overwhelming. There must be literally hundreds of different models. I was not successful in identifying my unhappy 20" model (I think I narrowed it down to two possibilities, but am not sure; the serial number identification didn't work for me). Attached is all the information I can glean about the 20" iMac. This is a
real screen shot, taken with a camera.

None of those wimpy "Print Screen" button pushes for me! (Can you even do something like that on a Mac?)
What would you recommend that I do?
tanstaafl.
edit: The 24" iMac has 6GB of RAM
edit 2: Added picture of "Leopards". Does this help matters? Will one or the other of these disks serve to nuke and repave the 20" iMac?