You can boot up from the Mac OS X Install Disc that came with your machine or using the Recovery system if you have Lion/Mountain Lion installed. In the Utilities menu that will be on the top of your screen after you boot to the disc, you'll have an option to Restore From Time Machine Backup.
Once you choose that option, it will perform a full carbon copy restore from your Time Machine backup.
"Restoring your entire system from a backup
If you are restoring a backup made by a Mac to the same Mac
With your backup drive connected, start up your Mac from the Recovery system (Command-R at startup) or Mac OS X v10.6 installation disc (With the disc in the optical drive, 'C' at startup). Then use the "Restore From Time Machine Backup" utility."
That sounds way too easy! I'm assuming I'd have to format the disk first then do the recovery from Time Machine? Recovering from Time Machine would also install ML?
I won't have access for months to an internet connection that would let me redownload ML, so I'm hoping you're right and restoring from Time Machine is all I need to do. If that's the case, I'm just 15 minutes for installation plus about 3 hours for recovery (and the time to run into town to buy a drive) to be right back where I was when my hard drive had its fatal stroke. I love Macs.
Moral of the story folks: have backups. I have two friends whose hard drives died and ended up paying $$$ for data recovery services that didn't get everything back (one lost 5 years + of pictures). It's not fun to be stuck on a Windows PC until the new drive is in, but I'm not even sweating this. Phew.
Thanks for the reply!