An interesting example of what a map mashup can be: the Gutenkarte site has an annotated map of the sites mentioned in HG Wells's War of the Worlds. (Hum the Jeff Lynne theme.. karaoke "the chances of anything coming from Mars... are a million to one he said..")
It's quite an interesting experiment; don't zoom in, because the detail isn't there. Do click on the named towns and places, and you'll get a wiki-style extract from the book. You'll recall that the giant cylinders landed at Horsell Common. Yes, you already knew that, sure.
Unfortunately (or not, you decide) the map doesn't go to a large enough scale to show Tom Cruise, even if he'd been in an English-based version of the film.
Perhaps you're wondering what Gutenkarte is?
Gutenkarte is a geographic text browser, intended to help readers explore the spatial component of classic works of literature. Gutenkarte downloads public domain texts from Project Gutenberg, and then feeds them to MetaCarta's GeoParser API, which extracts and returns all the geographic locations it can find. Gutenkarte stores these locations in a database, along with citations into the text itself, and offers an interface where the book can be browsed by chapter, by place, or all at once on an interactive map. Ultimately, Gutenkarte will offer the ability to annotate and correct the places in the database, so that the community will be able construct and share rich geographic views of Project Gutenberg's enormous body of literary classics.
So far it has various works by Dickens, Wells, Joseph Conrad (the horror!), Twain and Homer. (Thanks for the pointer to Ed Parsons of Ordnance Survey.)
