Jack Schulze provides this horizonless view of Manhattan:
Here & There is a project by S&W exploring speculative projections of dense cities. These maps of Manhattan look uptown from 3rd and 7th, and downtown from 3rd and 35th. They're intended to be seen at those same places, putting the viewer simultaneously above the city and in it where she stands, both looking down and looking forward.
Imagine a person standing at a street corner. The projection begins with a three-dimensional representation of the immediate environment. Close buildings are represented normally, and the viewer himself is shown in the third person, exactly where she stands.
It takes a minute to wrap your head around the concept, but it's an interesting one. It bet it'd be especially awesome if it were an interactive map that you could use while you roamed around a dense city. What do you think, cartographers?