Google Book Search has begun a project to automatically map locations from books. There was a post about it on the Booksearch Blog.
This is an incredibly cool addition to Google books. It is a little disappointing to see that places are mostly mapped down to the city level only, but then you realize that this is work done by robots and for robots, they're doing a pretty amazing job! The map of A Moveable Feast, with cities marked and page numbers listed for mentions of the cities, will be a great reference for someone who has too much time on his hands and a pretty good knowledge of Paris and London to pinpoint the scenes a little more precisely. In general the maps are wanting of a little human touch. I noticed a comical error on the Shakespeare map, where all mentions of the character Orlando from As You Like It are mapped in Florida. Memphis is unfortunately mapped in Tennessee, rather than Egypt and Syracuse is plotted in New York instead of Italy. Still, not bad!