I think I was able to cure my Windows 7 freezing issues for good (OK, maybe not cure, but bypass).
I disabled Aero and went back to Windows Classic. Hasn't frozen since. In my last post I hinted at a video problem - and I suspect that may have been it. With Classic enabled, the Aero "Peek" and other little things like that are disabled with the Aero package as a whole.
And like I said, it hasn't frozen since... going on nearly a week now. I couldn't get by 2 or 3 days before.