hello! the ibook 500 is also kind of fanless. it has one, but it was never on wihin the last 2 years And I also had one ibook 700, which only used it twice (for about 4-5 seconds) within 10 days. Not so bad. But the 800/900 machines do use it quite often , i think. Maybe that's also related to the graphic chip.
bye,claas