The German government recently launched an initiative to appeal to these Americans. German Originality is a site with heritage information and genealogical links for research. But the main feature of the website is the interactive map (guess which caught my attention first). One can view the various regions of Germany and click on towns for heritage and tourist information. One of Catholicgauze's German branches comes from the town of Hilter (yeah, I miss read that too the first time). While nothing is marked for Hilter the Pied-Piper Story historical event occurred right near by.
Sadly the website is not for those Americans of German descendant who's ancestors came from Austria, Switzerland, or the various "lost lands" of East Prussia, North Tyrol, and elsewhere. For more German heritage research be sure to check out the surname mapper.