From mobile devices to the desktop - AMD offers CPU throttling for everybody
It's always a good thing to not waste electricity, even if you're not relying on a notebook-battery. Even at home, on your desktop you might want to consider slowing down your CPU when it's not doing anything, and by that saving some electricity and producing less heat.
My new CPU, an AMD Athlon64 X2, has Cool'n'Quiet, which is, you could say, the desktop-version of PowerNow!. It can reduce the voltage and frequency of your CPU and increase it if needed.
The kernel offers the cpufreq-interface for this. With the cpufreq-utils you get the userspace-part of cpufreq, which is used to set the governor and frequency of the CPU. The governor is something like a profile. The performance-governor always runs on full speed, the powersave-governor on low speed.
In order to save power when the CPU isn't busy but have full speed when it's doing something the ondemand-governor can dynamically adjust the CPU-frequency according to what's needed.
As far as I can see Intel doesn't seem to offer frequency-scaling for it's desktop-CPUs, which I think is a shame. CPU-throttling is good, and seems not to have a big impact on overall performance. I can live with having the CPU switch to turbo-mode first when I start doing something that needs some more power.