Buy a conroe, they run very cool....

If your using the stock cooler and the stock gray colored crap they put on the heatsink, get yourself some good thermal compound and try reseating the cpu. Just remember, you want a paper thin amount of evenly spread compound on the cpu. Too much can be just as poor-performing as not enough. My last system had a p4 3.0 ghz prescott, and that processor idled at 50 degrees celcius and under stress, got as hot as 75 degrees!!! That processor was supposed to run that hot, I don't believe yours is...