> I'm thinking that maybe, a disk error caused SL to fail.
> Then from that point on I was trying to boot a disk with
> SL half installed...which of course failed.
That's possible, but I wouldn't be quick to jump to that conclusion. Snow Leopard has safeguards against that happening. It's designed to be able to finish an install and leave you with a bootable HD
even if the power goes out during the install.
> all I really need are the user files right?
That's usually the most important stuff. I'd try to get the Users, Library and Applications folders if possible.
> So I can wipe the drive. Reinstall the System. Then copy
> over the user contents into the new user folder. Anything
> wrong with that line of thinking?
Yes. That's not the greatest plan. SMART status is sometimes handy, but often WRONG. There's a very good chance that your drive has hardware problems, given the symptoms.
I would not trust that drive again.
And there's a way to import old user accounts when you have them backed up. After doing a clean install, make a new admin user (with a different name than the one you used for the old user account), copy the old user's Home folder to the Users folder on your drive, then go to the Accounts pref's and create a new user with the exact same name as your old user had. If you did it correctly, the OS should detect the old user folder and ask you if you want to use it for the account you're trying to create.
All of that assumes that you can successfully install the OS on the drive after erasing it. There's no guaranty of that. And since you don't know what's wrong with the drive or whether erasing the drive would really fix anything (or perhaps would just hide the problem for awhile), you might want to keep your present backup handy and institute nightly backups onto yet another hard drive if you're gonna keep using that drive.
...
If you've got a recent copy of DiskWarrior handy, using it on that HD could give you a fair idea of whether the drive is still useful.
