Here's a couple of Doctor Who locations sites that are so excellent that I want to crawl under a rock.
First www.doctorwholocations.net is fantastically comprehensive and very easy to get lost in. We even get links to the studios where filming was done and the dates that the filming happened. I links to the locations on Streetmap.co.uk, which gives you the map from ordinance surveys.
www.doctorwholocations.org.uk on the other hand is a Google Maps mashup. The interface is sort of clunky, but it's just about as comprehensive. And you can pull their file into Google Earth!
So in case you're interested, here are all the locations (in the UK at least) at once. Now if I post more, I'm just following up.