I have placed into the net my utility for making hi-packed PNG images from GIF,JPG,TGA and PNG. The utility corrects color troubles in palette of image to right show it on mobile phones of both LG and SAMSUNG during image packing. The utility works via Drag'n'Drop mechanism and enable convert as single image as a image list (so you can use it via command string too). It is a java utility and fyou need have JRE 1.5 or later to start GUI version.
It's free utility, you can download it from http://www.igormaznitsa.com