I'm American living over in Germany, there are a lot of clubs that you can join of various abilities, as the other guy mentioned you can probably find some decent military runner's in that area, I'm about an hour from where you'll be. I'm sure you'll be able to find some people to do some long to moderate runs with. Most of the clubs are open to the public so you just have to find out their schedule which is usually posted on the club's website and then show up and integrate yourself into the herd.
There are quite a few "decent" runners around, in my area there are a handful of 2:22-24 guys and around the corner is a French guy that is coached by a former 1,500m French champion. In Frankfurt there also is a lot of competitive runners and the Frankfurt Marathon is there also.
If your looking also to get into some races and looking at your competition's results this is a great site to browse:
http://laufinfo.de/