Thanks again John for pointing me in the right direction.
It was in fact the IBM Rescue and Recovery Backups that were taking up all that space. A full 30+ GB of backups... sheesh.
I can't speak for HP or Dell systems. However, for IBM/Lenovo users, after going through all this and finally sorting it all out, here is what I'd recommend:
1) Leave Windows/Vista System restore *ON*. Yes, it does use up some space, but on my last system (Thinkpad T40) it saved my *** more times than I can remember when I installed a driver or application which went psycho on me. When I turned it off in my tests, it saved me about 4-5GB of space, i.e. some but not that much. Honestly, with all the things that can go wrong with a driver or application install, sacreficing that amount of space is worth it. It's probably the best single feature MSFT added into Windows. If it starts using up too much space, just go in and delete the old restore points. It's fast and easy.
2) DISABLE the IBM/Lenovo Rescue and Recovery Backups. Go to the ThinkVantage Rescue and Recovery utility, click on "Set Schedule and Preferences" and uncheck the "Schedule Your Backups" box.
After Ok'ing that, on the main R&R menu click on "Advanced" and select "Delete Backups". You should see a list of backup files that it has made in the hidden RRbackups directory. Mine totalled over 30GB, over a third of my HD. Check the files you want to delete and click the "Delete" button.
*NOTE*: Do this when your Thinkpad is plugged in and you have a LOT of time to do it. When I deleted the first few files as a test, it took literally 2 1/2 hours for R&R to delete it. The odd thing is that when I went to delete the largest remaining file, it took all of 10 seconds. Go figure. So the point is, be prepared for it to take a LONG time. It may not, but just be prepared.
After all was said and done, I went from having 19GB of free space to 58GB of free space. *Much* better...
A final note on backups: I can't necessarily blame MSFT, IBM or Lenovo for what they did since many people just don't back their stuff up and then go screaming to their customer support lines when they spill their caramel lattes all over their notebooks. Instead of trying to back *everything* up like ThinkVantage R&R does, here is what I do:
1) I organize all my work in subdirectories under a single working directory
2) I got a 300GB Western Digital network drive for about $200 from Amazon and hooked it up to my router
3) I got a neat file sync tool from Allway Sync (http://allwaysync.com/) to backup my entire working directory tree onto the WD network drive. The first sync is rather slow because you are limited by the speed of the 100BaseT network interface. Later syncs go pretty fast since it only updates files that have been changed. After that, I configured Allway Sync to sync my files everyday at dinner time. I just leave my X60 on and my work is automatically backed up daily.
The R&R backup seems like a hamfisted way to approach backups. If my HD takes a dump, those files are toast anyways. If my HD went south, I'd have to reinstall my OS and applications which is a pain in the butt, but not catastrophic since my work is backed up on the network drive.