D.W.T.

One of the most common sources of human error is multi-tasking, especially when performed behind the wheel of a car.

D.W.T. or Driving While Texting, is a supremely bad idea; it's been implicated in the crash of a train in Los Angeles and a trolley in Boston.

It is also becoming illegal. In Utah, for instance, texting and emailing while driving are now punishable by a $750 fine and 90 days in jail.

The state has put out a video, which you can see here. There's also a similar, though very graphic, video appearing now in the U.K.

As the Wall Street Journal points out, companies are scrambling to come up with new texting-safety apps that block texts or minimize the distraction they cause.

But you don't need any of these; you could just hang up the phone and drive.