Shiny! Yes, it's an isochronic Tube map
Via those ever-wonderful people at Inky Circus, comes this: a Travel Time Tube Map. Most neat.
Isochronic maps basically have temporal contour lines, so that points further away in travel time are depicted as being further away on the map (there's a famous one for the Pacific that has Sydney and LA basically next to each other, while places like Vanuatu are effectively on Mars). This one morphs depending on which starting station you choose, which is fairly cool IMHO.
The write fesses up to making up the times for the DLR and says it's very much a work in progress, but has got synching with realtime Tfl data on the wishlist, so there might be more good stuff to come.