Does anyone know a tool to manually control the speedstep of a Pentium-M processor?

I'n in the train for 1,5 hour eveyday to go my work.

I work & play on my laptop in th meantime.

My battery can easely handle normal windows application since they are not very heavy my CPU speed slows down automatically and saves battery.
But some (maybe badly written) old application boost the processor to 100% allthough they dont need a lot of recources, but in the meantime these applications are draining my batteries.

So I would like a tool to manually control the processor speed to save my battery.

http://www.diefer.de/speedswitchxp/

On this site I found a freeware tool that can manually control the speestep.