Jack Uldrich at TCS Daily explores the idea of constructing a "space elevator" to quickly and cheaply allow humanity to lift items into low earth orbit. While the idea might appear crazy to most, many, if not all of the technical details have been thought out already, see here and here. Carbon nanotubes have already been created that would support far greater weights than that required for such a system. Popular Science had a recent article on the subject as well, and the primary issues preventing the construction of such a device appear to be mostly political and expense. Up to this point, no one has apparently had the gumption to make the thing at a cost of $12 billion or more.
"In its simplest form, the elevator would consist of a ribbon of super-strong carbon nanotubes be tethered to a large platform located near the equator and attached to a space structure at the other. To get from earth to space a cab would climb the ribbon."
However, it would greatly reduce the cost of lifting a pound into orbit from the current $10-20,000 per pound, down to something like $10 over time, as well as make it quicker and much easier. Uldrich compares our current rocketry system of achieving orbit to carrying bags of flour by horseback. The bigger issue is that 95% of the fuel costs of launching is eaten up just achieving low Earth orbit - the space elevator would solve that and allow us to go anywhere we wanted in the entire system, and one up those pesky Chinese on top of it. $12 billion, while not inconsequential, seems like a small price to pay for the future of space flight.