If you get a 3rd party CPU Cooler (Those Zalman ones mentioned are great) You also may want to get a good thermal compound to go between the CPU and the Fan. I've had good luck with the Artic Silver thermal compound. The thermal compound is what helps transfer the heat from the cpu to the heat sink and can easily drop another 2-3 degrees celsius off your CPU temp. I consider it cheap insurance in helping keep systems cool.