Last night I watched 28 Days Later, an uber-creepy zombie flick. (Warning: spoilers ahead.) Some of the most striking images in the movie are in the opening minutes, when Jim, the protagonist, wakes from a coma and discovers that the hospital is deserted. He walks out into the streets of London and they are empty. If you've ever been to London, you know this is never the case, especially in the London Bridge area. How did...