OK, I went ahead and worked some more on this (no new images to show off, yet). But, more info and the complete data set of Bavaria at http://meta.wikimedia.org/wiki/Geo to give you an idea of the internal workings. I'm actually using (media)wiki syntax to denote the data, so it stays humanly readable.
And, I now read my data from my local wiki (through URL, action=raw). Generating the half-German map takes about 2 seconds.
Tomorrow, I need to work on the parameters to call the thing. As you can see, I can already state to draw Hamburg in red. But, I want to see the surrounding parts of Europe in one color, Germany in another, and Berlin in yet another one. And to draw an extra border around Germany as a whole. This will prove tricky.
Also, for drawing parts of Europe, I need more data. And a city drawing routine. and some rivers and lakes. And the ocean. Geez, why do I always get myself into such a mess ;-)
Magnus