As I write this message, my Powerbook G4 800 fan is on full blast. The case is extremely hot; I can't hold my finger to the section of metal between the keyboard and the display for more than a second it's so hot. CPU load is less than 0.2, usage is under 10%. All I have open is Safari and iChat.
My Powerbook used to have overheating issues a few months ago, but it only happened when I was really pushing the CPU--compiling or playing games. Now all I need to do is have the system on for 5 minutes and it will severely overheat.
This has been going on for two weeks now and I have no idea how to mitigate this. Nothing I do seems to get the laptop to cool down; the fan may become more quiet but it's still uncomfortable to type on because the keyboard is so warm.
I love this laptop. I've had it for about 2 years so I know I'm due for a replacement. I'd buy a replacement today but I know the G5 Powerbooks are just around the corner...
I'm considering getting a PC laptop because all of the code for my thesis is done in Win32/Direct3D, but something about going back to a PC laptop just doesn't feel right. :-) Certainly, in PC land I can get something much more powerful much cheaper, but I love the Mac toolset for email, writing (LaTeX), and web surfing... Also, PC laptops don't have exactly have a better track record for reliability... :-/