An inflatable tower in place of a space elevator?

That's the theme for an idea explained here. It's a pretty simple concept - use super strong materials to create a tower that could be inflated and extended to a height of about 15 km (or up to 20 km if constructed on high enough ground), which would then be used to decrease launching costs since 15-20 km above the surface of the Earth is already above most of the atmosphere.

With enough helium it's definitely doable, and would be much easier to construct than a space elevator, but I still prefer the JP Aerospace approach, which would be able to reach space using airships alone. The JP Aerospace concept is this: use a regular airship to go up to a certain point (a midway station), then transfer the cargo to a much, much larger airship powered also by electric propulsion to carry the cargo the rest of the way.

Another approach is to simply create a type of floating launching platform that would carry a rocket up to a certain point where it would then launch from, perhaps in the same way SpaceShip1 launches - it gets carried up to a certain altitude, is dropped, and then fires its rockets to take it into space.

A tower some 15 km in height though would probably be more interesting simply as a tower, since that would be a full 18 times the height of the Burj Dubai. See:

The Burj Dubai is that little red thing next to this extremely lengthy tower on the right. The other towers are the CN Tower, Taipei 101, etc.