Joel on Software said he recently visited the new 7 World Trade Center building, which includes new computer dispatched elevators. Here's how he describes it:

Instead of having up and down buttons outside the elevators, there's a numeric keypad, where you key in the floor number you're going to. Then an LED display tells you which elevator to wait for. Once you get in the elevator, you don't have to press any buttons (and there are none to press).

Anyone who, like me, has played hours of SimTower knows that when people are coming or leaving in large numbers, the elevator system can be very inefficient. With this system, a central computer plans trips to neighboring floors instead of just going up or down. According to the Wikipedia article, these new elevators may reduce travel time by 30%. Sounds like some cool stuff.