Reusable rockets

I have long thought that the most important thing for NASA to be doing is improving the ability to get cheaply into space. I have long known that there in a whole lot of efficiency improvements allowed for by the laws of physics making it reasonable to foresee a world where getting to space costs a similar amount to flying around the world.

This question and answer session really made that clear to me

"We are trying to achieve full and rapid re-usability. If we can make fully and rapidly re-usable rockets that are cheaper to build than expendable rockets are today, then we will only be worried about the fuel, and the propellant cost per flight is only 0.3% of the cost of the mission."

Right now we are not paying for energy, we are paying for engineers and expendables. Once a fully reusable space ship exists the drop in costs should be dramatic.