This could be exciting, or it could just be science fiction.
Rand Simberg thinks that we have a little further to go (presumably, before the concept is useful).
Arthur C. Clarke, interviewed in the Times of London:
In 1969, the giant multistage rocket, discarded piecemeal after a single mission, was the only way of doing the job. That the job should be done was a political decision, made by a handful of men. (I have only recently learnt that Wernher von Braun used my The Exploration of Space (1952) to convince President Kennedy that it was possible to go to the Moon.) As William Sims Bainbridge pointed out, space travel is a technological mutation that should not really have arrived until the 21st century. But thanks to the ambition and genius of von Braun and Sergei Korolev, and their influence upon individuals as disparate as Kennedy and Khrushchev, the Moon — like the South Pole — was reached half a century ahead of time. If Nasa resumes lunar missions by 2018, that timing would be just about right: it will be only a year short of the 50th anniversary of Neil Armstrong’s famous “one small step”. But banking on solid rocket boosters to escape from Earth, as being planned, will not represent a big technological advance over the Apollo missions. Even if the spacecraft are reusable, it will still cost hundreds of thousands of dollars to launch every kilogram into space. I think the rocket has as much future in space as dog sleds in serious Antarctic exploration. Of course, it is the only thing we have at the moment, so we must make the best use of it.
But I would urge Nasa to keep investing at least a small proportion of its substantial budget in supporting the research and development of alternatives to rockets. There is at least one idea that may ultimately make space transport cheap and affordable to ordinary people: the space elevator. . . .
As its most enthusiastic promoter, I am often asked when I think the first space elevator might be built. My answer has always been: about 50 years after everyone has stopped laughing. Maybe I should now revise it to 25 years.
(hat tip to Instapundit).