
Cool, right up my alley! I like this very much, much cooler than the one i hacked together. Do you know if it would be possible to render a special LARGER more detailed image when save to PNG is pressed?

It's possible, but would probably be slow. (512x384 would take approx 4x as long to render for example). In theory, since libpng supports writing a single row of data out at a time, I could render as big as an image as I want, as long as I can fit 1 row into RAM at a time.
What about an option where it will save out your current position & zoom to a text file, then a PC side renderer which reads in those settings and produces a very high quality version? It could produce giant sized (compared to DS) images in just a few seconds.