Knowing how to time stoplights is a key element to driving. You don't want to stop completely at a stoplight when it's just going to turn green immediately. That's a waste of gas! You want to slow down just enough to catch the light as it's turning green again. It's the efficient way to drive, don't you see.
Well, Audi is currently testing out an ingenious system that would tell you exactly when lights you're approaching are set to change. The "Travolution" project networks cars with traffic signals wirelessly, showing you exactly when the upcoming light is going to change and how fast you should be going to clear it. This will not only improve fuel efficiency, but it should make traffic flow a lot smoother. How awesome would it be if this became standard in all cars and on all roads? Maybe someday.