That is the popular term (to the extent the word poular can be used for this space exploration concept) for the idea that we can run a wire from the earth to orbit and just run things up and down the wire.
There is a new book out on this concept and related ideas, reviewed at this web site. The book is Space Tethers and Space Elevators, by Michel van Pelt (Praxis, 2009, $29.95)
I thank my Brother Lance for pointing out this web site.
Regards — Cliff