You might be able to make use of my PowerSchemeToggler:  http://www.donationcoder.com/forum/index.php?topic=19847.0

skwire, I really apreciate your reply. I will download when come home cause there´s a firewall in my job.
I am wondering if I can use two instances of CpuIdle to trigger powerSchemeToggler when cpu is idle (<30%) and not idle (>80% - how can I set this? can I use logic operators as = > < >=);

any suggestions will be wellcome. I will give it a go.