Fan? What fan!...

My iBook fan came on for the first time ever last night... after about 7 hours continual use. I didn't even know it had one in there (doh!)... is this normal? The iBook normally runs completely silently even after this amount of time.

yeah, it's probably normal. If you're doing some gaming or any processes that require more juice, the fans usually come on. Typing this, I can't hear the fans on my macbook, but if I were to launch a game, they probably would come on after some time. Photoshop also causes the fans to come on sometimes if you're working with large files, doing filters and all that. You were probably just doing something more CPU/RAM demanding.

So it's not really about how long the laptop has been on for, but what it's currently processing.

Thanks... I was photoshop-ping..

yep, that would have done it then. I get it all the time when I'm doing stuff like that. It's nothing to worry about.

you will also get the fans turning on when watching a dvd
or rendering video files