Did you know that the Google Streetview cameras have been inside a number of UK railway stations, including St. Pancras International? Here's the Eurostar check-in entrance, for example.
Most of the main London terminals are covered, plus Edinburgh, Glasgow, Liverpool, Leeds and Manchester. Gatwick Airport is also featured, but not Heathrow as yet. There is an interactive map showing all of these new locations, from which you can see it's not just the UK - a lot of large Italian railway stations have been covered as well, amongst other places.
Anyway, I just thought this might be useful for people who like to do really detailed route planning.