Turns out the problem was bad ram.  Thanks orthorim.

I removed my NewerTech 8GB RAM from OWC, and replaced it with the original 4GB that the machine came with. Guess what – everything is hunky dory. No problems. Machine has been running for hours without crash, and I placed some stress on the RAM too.

I am now running on 10.6.6

Lesson learned: Don’t trust 3rd party RAM. Or at the very least, do some research before buying. See this thread on other issues with this RAM: http://discussions.apple.com/messageview.jspa?messageID=12948299&stqc=true

For my next machine, I’ll just buy the RAM from Apple. It’s overpriced, but in the end anything would be cheaper than spending 2 days installing, and re-installing, and testing my system.

via Apple – Support – Discussions – 10.6.5, 10.6.6 Kernel Panic ….