if you have experience writing Gimp plugins and you know how to specify image types handled by a Save-type plugin, email me the info.
For general use examples see http://www.ne.jp/asahi/linux/timecop/loader.html
The save function does absolutely no error checking. It currently handles normal RGB, RGBA, and INDEXED type images. It can save RGB and RGBA the "normal" or "planar" way. It can save INDEXED the "normal" way + add a filename.pal with the pallete in either standard RGB or Windows BGRx format. If it crashes, you must fix the save function by adding a whole bunch of error checking and send me a diff -u
Also if you are a GTK programmer you should rewrite both load_dialog and save_dialog and make them less ugly and send me a diff -u, too.
-timecop