Since Paint.Net has a bug where the selection box ends up off-set in really huge pictures and it won't zoom in all the way... >:( (256x40960

BTW- I found a program called "photofit" but for large playerships it's too limited (max area is 350000k pixels)
Also, another possibility is ArcSoft panorama maker. It's limited to doing 120 images, enough for most purposes. Hmm... it doesn't work the way we need it to... It does make good panoramas from photographs though...