j3ff, did you try using powerstrip? I used ATITool and i couldn't even OC 5MHz before the computer locked up on me. I'm finally done OCing... Here's what I found, at least in Mark03:
Score: ~3550
OC: 480core/268mem (if i set the slider maxed out at 270, it drops down to 216. So 1 notch down is 268).
This OC REALLY surprised me. 480 core is insane! 485 crashes mark03. It'd be nice if I could pull more MHz out of the memory, but I really don't think I'm going to OC this laptop that hard on a regular basis while playing games anyway. I'm just doing it to check out how far I can push it. No artifacts whatsoever though. I was looking really hard in game 4 and PS2.0 tests and there was nothing. Very impressed with the GPU I got.

I'll try out Mark01 and Aquamark later I think just to grab some scores.
I think when I'm regularly gaming, I'll stick to about 450/250.