Tonight's Evening Standard published a photograph of London by night, taken from space. It was a high-resolution pic from the NASA site - the same people who brought us the Blue Marble project. And if you don't know what the Blue Marble project is, stop whatever you're doing right now, and go download the highest pic of our world from space that your system can handle.
The image of London by night available on the NASA site is quite lo-res, but after a bit of searching, I think I've managed to find a more detailed one. Check back here in an hour or so, as I hope to make it available, pointing out various London landmarks.
Update, one hour later: Bugger that. I can't seem to line up a street map with the vague illuminated main arteries on the satellite pic. But Steve has created a cool little Flash toy with it.