Here. For a slightly different look (and if the red arrows get annoying),
here and for a quite different one,
here.
The best thing to happen on this way to the future would be for someone to write a functional renderer of
NED on top of OpenStreetMap;
TopOSM just doesn't cut it. It must be a really hard problem to solve.
(The actual paper map for the event had 10 m contours, derived from the NED.)