A: 
Bundle bundle = Platform.getBundle(pluginId);
URL fullPathString = BundleUtility.find(bundle, "icons/palette_brush.png");
ImageDescriptor.createFromURL(fullPathString);

pluginId is the id of the plugin where you put your icon.

nanda
thanks a lot! This is how i finally did it: ImageDescriptor icon = Bundle .getImageDescriptor("icons/palette_brush.png");
Gnark