In the “data is fun” category, view what one Google software engineer Matthew Gray created to “"to show the Earth viewed from books, where individual mentions of locations in books combine to yield another interpretation of the globe."
You can view the result and also examples of filtering the map by publication date.
Meanwhile, Google has added its 13th participant for the Google Books digitization project, the Bayerische Staatsbibliothek (Bavarian State Library), “one of Europe's most important and renowned international research libraries.”
This is the largest non-English library to join Google's efforts. The library will offer up a wide range of its public-domain titles -- including books by Goethe and the Brothers Grimm, more obscure German works, and a smattering of volumes in French, Spanish, Latin, Italian, and English -- to the search engine, according to the Inside Google Book Search blog.