I have a Q6600, is it the G0 stepping one thats good for overclocking.?

Im looking at building a new PC in the new year running an I7 extreme with 2 Ati HD5970 or similar cards, solid state discs etc etc... Will be looking at dabbling a little with the OC on that.

My mate is right into the OC.. He tells me tales of people cooling the CPU with liquid nitrogen to push them up to silly speeds..