I have made my own B/W icon for
Computer
I made it with a program called
Icon Composer, that happened to be on my drive. I think it is installed with the Dev-tools.
Just open this program and take a 32x32 picture and drop it in the apropiate Icon category.
There are Icons for 16x16, 32x32 and the 128x128, that you can put in such a .icns file, for the Icons in the bar, you need the 32x32 ones. on the right of the Icon, you can add a 1bit (Black/White) graphic that specifies the
hit-area of your Icon.
Then save the file with the apropiate name (i.e. computer.icns), and copy it to the folder glowurm mentioned earlier (I did this via Terminal with sudo cp)
Picture of my Iconbar
I also made myself a nice bootpanel, by replacing the file
/System/Library/CoreServices/SystemStarter/QuartzDisplay.bundle/Resources/BootPanel.pdf with my own.
Screenshot
The Loginpanel is located in
/System/Library/CoreServices/loginwindow/Resources/loginpanel.tiff, btw