For Ubuntu 11.10
The first thing you would need to do is take a .png icon file that you would like to use and copy it to the respective
~/.local/share/icons/hicolor/ directory. This will contain the following directories (which are the dimensions of the icons) :
I downloaded a free 16x16 free icon sampler and picked a 16x16 icon called
I took the
Alien.png file and copied it to
~/.local/share/icons/hicolor/16x16/apps, When you copy yours, you can do that through either the GUI or terminal.
From there you would need do the following in a terminal (you may need sudo to copy this over):
cp /usr/share/applications/pidgin.desktop ~/.local/share/applications/
Next edit the pidgin.desktop file:
Look for the line that says:
This will need to change to the new icon name without the .png prefix...
Save your changes... Then logout and log back in.
Please let me know if this helps or if you need more assistance.