Earth based mass driver, but not as we know it.

Launch loop:

http://en.wikipedia.org/wiki/Launch_loop

http://www.launchloop.com/

Basically, a big launch loop puts things into space for around $3/kg. With
current technology, it takes about 1000kg of (reusable) capsule to support
one person in space, so that's about $3000 to put you into space. There's
very few people that can't afford that. The launch g-force is 3g- anyone and
their grandmother can survive that.

There's some technical risk-nobody knows absolutely sure it can be built,
but only really because it's never been done before, there's no known show
stoppers (unlike the Space Elevator which has at least one total stoppage-
the lack of suitable cable; and then there's the radiation). And it can be
tested at fairly small scale before deploying the full system.

If you're really, really lucky somebody will build one to launch solar power
satellites, and then space settlement is right behind.

Oh yeah, and it's probably cheap enough that it could be used for suborbital
as well, so you could go to the opposite side of the Earth for less than it
costs at the moment, as well as it being more environmentally friendly (it
uses less energy than flying because it's above the atmosphere).

--
-Ian Woollard

We live in an imperfectly imperfect world. If we lived in a perfectly
imperfect world things would be a lot better.