Hard Disk Usage App


I have a G4 iBook and I find it slightly annoying not being able to tell when the hard disk is active without putting my ear too it. Is there some small app that would let me know when the hard disk is in use? Maybe put a light on the bar at the top of the screen?

With OS X, that's pretty useless. The hard drive is accessed quite a lot during boot, of course, and during normal use. So you would have a light much like a network access light, that would flash intermittently much of the time your computer is in use.
You can open Activity Monitor, and set that so Disk Activity displays in the Dock icon.
With 1024*768, he probably hasn't set the Dock to be always there... But I agree in that I find such activity icons pretty useless. Norton (don't use any Norton software, please!) once had "Disk Light" back in the days. Part of Norton Utilities, I guess... Either way: When do you _need_ to know whether the harddisk is actually working? Only if you expect it not to and want to know whether your computer crashed?
In Linux, they have a kernel module that is basically a hack, causing the sleep LED on the Powerbooks and iBooks to act as a disk light. I thought it was pretty cool :)
Tenson- I believe MenuMeters ( http://www.ragingmenace.com/software/menumeters/ ) is what you're looking for. It has extremely customizable indicators for CPU, Disk, RAM memory usage, and Network activity. And just when you thought it couldn't get any better... it's free!

Love it. I cannot espouse MenuMeters enough. :D

EDIT: Hey, Viro, what kernel is that? Any way to adopt it to Mac OS X?