I hate to derail, but I have been wondering this. Why do people spend so much money and effort to overclock?
In some (not all) cases you can save money.
Example: last year when the Core i7 chips were just released, you could buy an Intel Core i7 920 (2.3 GHz) for $200 from MicroCenter and overclock it to 3.3 GHz on air, which is about the same as the stock speed of the Core i7 975. The price of the Core i7 975 at the time was $999.
A good air cooler would cost you $60-80. Let's say you also add a few 200mm fans and you also buy a premium case to improve airflow. Call that another $100 over the price of a "standard" mid-tower ATX case.
Cost savings: $999 - ($200+$80+$100) = $619
Obviously this is only one example and not indicative of the entire CPU market. Further, the overclocked i7 920 may not be as stable as a non-overclocked 975, especially in warmer climates during the summer. But you can save some serious bucks!