Stations
Von Braun's.
2001's
Why did the Panam Clipper need to rotate for docking when an axis could have prevented that?
What about the Coriolis force ?
Why need the pods inside Discovery-1 when the astronauts went out anyway?
At least, the Space Station V had a flat floor, contrary to Von Braun's station!
But we're no more in 1952 or 1968, we're in 2009 and with lots of technical and practical reasons why they didn't materialize.