I saw something about this about a year ago in Time Mag. Pretty cool
What a strange concept. The idea of having a space elevator has always fascinated me since the day I played "Civilizations: Call to Power" in the summer of 1999. In CCTP, there is a structure called the "Star Ladder" that is placed in the middle of a major metropolis in the not-to-distant future. The only differences between the Star Ladder and the Space Elevator is the fact that the Star Ladder ended at the entrance of a orbiting space colony and was placed in a urban area.
I think it's a practical idea, though. It's almost guaranteed to stay standing because of the imbalanced relation between Earth's gravity and the zero G in space. Oh, and the nano tech, of course.