Great entries so far guys. Here's mine for this assignment.
Taken at Notting Hill Gate train station in London during December last year while waiting for the tube. I stopped down to f/11 with ISO 100 to try and get the shutter speed long enough to show the movement of the train coming in while still making it short enough for me to handhold and get a reasonable result.
Notting Hill Gate in Mono by Ben__Taylor, on Flickr
Enjoy,
Ben