Take Google Earth and add a Google Book Search layer and you can do some interesting things with teaching literature.
Google Books has a "places mentioned in this book" feature that uses a map to show you locations referenced in a particular book. Now, with the new Book Search layer, you can flip that over and use a map of a place and find the books from there.
If you're anything like me, you like flying around the world in Google Earth (same thing in Second Life - I read a lot of Superman comic books as a kid) and now you can browse books as you travel from place to place.
For example, check the books out in Canterbury, UK. Since all the books in this layer are public domain, if you find something you like, you can browse the full text online or the PDF to read the book at your own pace.
I really used to enjoyed having my middle school students create settings maps from novels we read. Mapping books with real locations is good, but books with imaginary settings are a lot more fun and far more challenging. I think it not only makes the settings real for students, but it's also a tremendous problem-solving exercise.
The Book Search layer isn't limited to fiction. I walked through the map for The 9/11 Commission Report recently which contains places in New York City and around the world.