Matthew Somerville has done a bunch of cool stuff as well as this:
http://www.dracos.co.uk/
Just this weekend I stumbled onto his site again when wanting to know where the nearest postbox to my new flat is.
Incidentally there is an official "real time map":
http://journeyplanner.tfl.gov.uk/im/RD-T.html
It's less cool, but actually tells you at a glance what you really want to know: where disruptions are.
Thanks :-) It would definitely be good if the map could at some point highlight disruptions, or closed stations/lines, yes (along with other things it could show, such as trains at depots if we know where the depots are). Source is available at http://github.com/dracos/underground-live-map :)
Incidentally there is an official "real time map": http://journeyplanner.tfl.gov.uk/im/RD-T.html It's less cool, but actually tells you at a glance what you really want to know: where disruptions are.