What would be the most simple way of adding and changing an icon in the Ubuntu (Gnome) Panel? I'm looking for something as simple as shell scripting, but I'm not restricted to that. Will write a program for it if that's a better or simpler approach.
The idea is to create a script/program to monitor some condition (e.g. availability of a mount point, availability of internet connection), and change the state of the icon to reflect the current status.