Imagine what your life would be like without GPS. It'd be like the dark ages, with everybody wandering around, eternally lost. Now, imagine what your life would be like with even better GPS. It's called GPS III, and the first of 12 new satellites will launch in 2014.
The biggest improvement that we can expect from GPS III is that the satellites' transmitter power will be increased by a factor of 500 over the current constellation. While this is primarily intended as a defense against jamming, a side-effect will be that you'll have much better luck getting a good signal in cities, under trees, and even indoors. This raises exciting possibilities for augmented reality on mobile devices, as well as for autonomous navigation on household robotic platforms.
Along with the signal strength boost comes a doubling of accuracy, which means that when you fix our position using multiple satellites, you can expect to know where you are within two feet instead of today's 20. So, your GPS will be able to tell not just what road you're on, but what side of the road you're on, and potentially even what lane you're in, or if you're driving on the sidewalk (oops).
The other cool thing about GPS III is that its signal is designed to play nice with different global positioning systems, including Europe's Galileo system and Japan's forthcoming Quasi-Zenith system, which would allow for one receiver with one antenna to use positioning information from multiple systems at once to increase accuracy. Russia is also working on their GLONASS system, and some receivers will be able to grab that, too.
The first of Lockheed Martin's 12 new GPS III satellites will probably launch sometime in 2014. Below, feel free to suffer through one of the most useless PR videos I've ever seen from Lockheed Martin on GPS III.