If you have a laptop with a Centrino or AMD64 processor, you may want to use rcconf to enable powernowd, a fantastic power-management daemon. I started powernowd and watched in amazement as my CPU temperature dropped by 15 degrees Celsius in 10 minutes.
This might be a good time to point out just what tool I use to find out the CPU temperature. I use (drumroll please) gkrellm, which actually reports a number of interesting things about your setup. In its default configuration, gkrellm doesn't display CPU temperature, but you easily make it do so by right-clicking on "CPU" and choosing "Sensors--> Temperature" and clicking the box saying "thermal_zone/THMO".