Smartphones... I understand it's useful occasionally to have the internet access wherever you are, and some people have a boring commute to work so it helps, but...
The other day as I approached a roundabout in my car, a woman drove across it perpendicular to me, I saw the glint of something in her hand, then I saw that while steering round the roundabout, using her left hand, she held a phone in that hand and her right hand was operating the touch screen.
Now, it's illegal but the police don't really take it seriously yet for some unknown reason. It's bad enough them talking on a phone while on the straight, they do wander left and right and are terribly distracted... but we are on a new level when idiots like that woman can operate the interface while perfoming a complicated manoeuvre that requires full attention.
I've seen a family in a restaurant and the parents did not say a word, they used facebook the whole time until their food arrived, then ate the food then got straight back on facebook again.