You're correct, MZ... to a point. If you want to OC, and do it right, you need to have the hardware that will do it. Cooling it is just part of the game. Good ram that was made for performance will benefit greatly from cooling if pushed beyond it's posted limits.

If you take some good Corsair or Mushkin RAM and test it next to, say, PCY RAM you can buy at Best Buy, chances are you will push the Corsair and Mushkin MUCH farther than the PCY, whether with RAM sinks (that don't do much, anyway), water cooling, or even a fan blowing past them (although the two latter do help).

I have some OCSystem PC2700 in my machine right now, and it won't do much past 270mhz without keeping the system from booting.