Are you fed up waiting for The GIMP to load when all you want to do is
change 3 pixels in an icon? No, you're probably not. But if you are,
then maybe GNOME-Iconedit is what you need.

Features:
* 256 level alpha
* 16.7 million colours
* Saving in XPM and PNG format
* Some fancy paint modes.
* Multi-level cut/paste buffer.
* Brush mode where contents of the paste buffer can be pasted
  anywhere on the screen.
* Loads any format Gdk-Pixbuf can handle.

WWW: http://www.abdn.ac.uk/~u07ih/gnome-iconedit/