See those black fins moving on the surface of this Falcon 9R rocket? That's SpaceX's magic sauce. These steerable surfaces will allow used rocket stages to safely land back on Earth, ready to be refilled and launched again. This on-board video of their new 1km high test show how they work.
According to SpaceX, this flight was their "first test of a set of steerable fins that provide control of the rocket during the fly back portion of return. The fins deploy approximately a minute and 15 seconds into the flight, and return to their original position just prior to landing."
The next phase of development will be the testing of the retractable legs. Right now, the rocket launches with the legs already deployed, but soon the company will "transition to liftoff with legs stowed against the side of the rocket with leg extension just before landing."
After that they will launch to higher altitudes, testing return without power, guiding the vehicle without the help of the rocket engine for most of its return trajectory.
I don't know about you but I find this all terribly exciting.