tileset maps
 

How about, instead of being restricted in the placement of tiles on a tileset, people could map (with colors) which tiles they want to do what. Making it the same size as the tileset, or it could be just a ratio size so you don't waste space. 16x16 pixels changed to 1 pixel.

I don't think I quite understand what your idea is... Could you be more specific or perhaps show a screenshot circling what you want to change?

http://home.comcast.net/~jake13jake/storage/ex.png

yea... lets pretend we had a tileset with wall tiles in the top left, lava tiles in the top right, land tiles on the bottom right, and water tiles in the bottom left. What if you didn't want to stray into the restrictions of the pics1.png set or the optional type1 tileset? Maybe if you could make an image that set the tilesets restrictions instead of having the tileset's restrictions set for you...

Also, It would be a lot simpler than having to make up a script that divided which tiles did what (and I don't think even THAT exists). Tilesets are more graphic-based than scripting-based, you know? Either way would be an improvement, though.