I don't know if it will prove at all practical, but if it does, the Möbius strip-shaped library building proposed for Astana, Kazakhstan may be the coolest building ever.
For those with a low math-geek quotient, a Möbius strip is a surface, like a strip of paper, given a half-twist and formed into a ring. In this way one side becomes the other -- in effect, the strip only has one side!
In the case of this building, the exterior is continuous with the central courtyard, and the walls become the roof.