Wow. 19 photos by London photographer Jason Hawkes, shot from a helicopter with gyro-stabilized mounts...
http://www.boston.com/bigpicture/2008/08/london_from_above_at_night.html
The photographer's
site is pretty spectactular.
There's a BBC video about the making of the "London at Night" series (linked on the front page) but it's limited to UK viewers- maybe somebody over there can let us know whether the video's any good!