I was thinking that Stefan should implement a new tileset format or something. Here is my idea...the current image is still in .png format, but you change the extension to .til or something and then use a special program that loads the .til file. It would of course show the tileset image, but you could then define what spots on the image do what (tile definition). the saved file would then contain the image and the definition for each 16x16 part on the image. Of course that could present problems, but you could make it so that they are only accessed when online and don't download. You could easily make the tilesets smaller then since not all levels use snow, castle, or lava tiles.
My idea is not perfect, but it is something to at least think about
