Here's another thing I'll add to my list of "mandatory stuff" once I become dictator of the world. From Boing Boing gadgets:
In 1936, Australian civil engineer Charles Marshall designed an analog, rotary traffic signal that was widely used up until the 1970s. I love the elegance: it's simply a one-handed clock that quickly sweeps through color-coded green, yellow and red signals. It also has the advantage of conveying to drivers exactly how much time they have to fiddle with the tape deck, apply lipstick in the rear view mirror or verbally abuse their spouse before the drivers behind them lean on the horns.