Just so everyone knows, the new version of SpeedFan has incorporated core temperature readings for Semprons, Athlon 64's, and Opterons. It's a much more accurate measurement and updates very quick; I'm using it right now and it is great! Just thought I'd point that out to everyone, if y'all don't know already.
http://www.almico.com/sfdownload.php
http://www.almico.com/sfdownload.php