I like this server: http://www.verwandt.de/karten/

This is a statistical evaluation from the German telephone directory. If you type a surname in there, you will see how often it occurs in each region - the server draws a map.

Die 6 häufigsten Namen kommen von Berufen:
The 6 most frequent names derive from proffessions:

1. Müller
2. Schmidt
3. Fischer
4. Schneider
5. Weber
6. Meyer

oder/or
1. Schmidt/Schmitt/Schmid/Schmied
2. Meyer/Mayer/Meier/Maier
3. Müller
4. Fischer
5. Schneider
6. Weber