Setting the CPU frequency of the Pentium M

My notebook's processor is a Pentium M. I specifically bought that notebook because the fan does not come on under normal use. This is very nice, simply because it's very quite. By setting the CPU speed to a lower frequency I might completely avoid the noise of the fan. This is what I did to be able to easily control the CPU speed from an applett in the gnome panel.

Firstly, I needed certain modules in my kernel, more specifically these:

- Power management options (ACPI, APM) --->
-- [*] Power Management support
--- CPU Frequency scaling --->
---- [*] CPU Frequency scaling
---- <*> CPU frequency translation statistics
---- Default CPUFreq governor (userspace) --->
---- 'performance' governor (1)
---- 'powersave' governor (1)
---- 'ondemand' cpufreq policy governor (1)
---- <*> CPU frequency trable helpers
---- ACPI Processor P-States driver
---- Intel Enhanced SpeedStep
---- Intel Speedstep on ICH-M chipsets (ioport interface) (2)

Notes:
(1) = Not sure if this is really needed.
(2) = You may want to adjust this if you have a different chipset.

If you're aiming for low noise (or long battery power) you will also want to change your default governor from "performance" to "userspace" as indicated above.