The use of smart digital technology in cars is big news at the moment - I think the danger of stuff becoming more intelligent than its owner is imminent. It happened 12 years ago for me with the Amstrad Emailer.
However, some technology has great potential for good.
Consider the video image capture devices (or "cameras" as I believe they used to be known) prevalent in cars nowadays. Over the last 10 years "facial imaging" software has grown from a specialist professional thing to become commonplace in even the most basic camera phone. Number plate recognition, which once seemed almost magic, is now old hat and used in many car parks. Cutting edge research is now taking things one step further into software capable of recognising human facial expressions and gestures.
So here's my idea.
All cars should have a camera on board which operates all the time the engine is running. When you are in a queue of traffic and you decide (out of human decency) to let another car in from a side street, the camera is able to detect the expression and gestures of the other driver.
If they make eye contact, smile, wave and do a Paul McCartney double thumbs up, then all is well.
If they calmly drive out in front of you staring firmly ahead with a sense of entitlement (or even if they merely lift one finger off their steering wheel), then your camera will detect this and read their number plate. This data will be forwarded over 3G/4G to the area traffic police who will track down this driver, summarily confiscate their vehicle and leave them to walk home.
In a spirit of schadenfreude a video of the police action will be forwarded to your email account to be enjoyed at leisure.
No, don't thank me....