SF has been blessed with many cool ideas that double as exciting settings for dramatic stories. One relatively rich vein for these stories is the Space Elevator (or Beanstalk, or Skyhook) which has been used to propel some great fiction. Here's some of them.
From GSV Three Minds in a Can on usenet
My understanding is that a 'skyhook' is a rotating beanstalk, which doesn't touch the ground - something with 2 or more arms, which dip into the gravity well as it rotates ... you leap off the ground, grab an arm, and get dragged up into the sky, where (at an appropriate point) you let go. The reverse for getting back down.. [more]
Lift Ring or Ring Around the World
From Scott Beeler on usenet
That brings to mind a wonderful vision of a vast series of beanstalks like bicycle spokes around the Earth's equator, supporting a continuous-band space habitat ringed round the planet. [This shows up near the end of The Fountains of Paradise]
Here's a good article from wired about Seattle company, Highlift Systems' plan. Dr. Bradley Edwards and Eric Westling recently relased a book called The Space Elevator which has alot of detail -- this sucker's pretty fully worked out.