How to Control the Fan of your PowerBook

Several small application, mostly freeware or shareware, are available for the Intel-based notebook to control the rotation speed of the embedded fans; mostly to keep the computer cooler.
This feature can now be used on PowerBooks and iBooks thank to g4fancontrol.
In its last version 0.3, one can set the temperature limit from which the fan should start spinning with the following command:

sudo ./g4fancontrol set 30

The value "30" defines the temperature expressed in Celsius degree (International standard)