I had to use Time Machine to recover my 10.6 Mac. Two little issues:

1) Quick Look didn't work. It would open up the big grey rectangle but not show anything--pictures, movies, PDFs, Excel files, nothing worked. I was at 10.6.1 and 10.6.2 was out but installing that update (and all the rest available at the time) through Software Update didn't fix it. A tip here http://reviews.cnet.com/8301-13727_7-10398867-263.html suggested downloading and installing the combo update (also for 10.6.2) and that cleared it up. ("Combo Update" is Apple's term for "everything since the last .0", so the 10.5.8 combo update can be run on any system, 10.5.0-10.5.7, and it'll work.)

2) The system folder "/private" was visible in the Finder at the root level of my hard drive. Not a big deal, but since I never need to go there there's no need to see it all the time. Running "sudo chflags hidden /private", as suggested here http://forums.macrumors.com/showthread.php?t=648139 did the trick.