But he hasn't quit his habit of racing solo at top speeds on closed courses.

WSJ: Toyota Chief Akio Toyoda Grabs Wheel to Turn Around Humbled Auto Giant

This is an earlier testing stage - although anti-smoking campaigners say it could be of significant help to those battling to quit the habit.

BBC: Cocaine vaccine trials progress

However, while people quit smoking in the UK, in many developing countries the habit is catching on fast.

BBC: UK lung cancer deaths halved

Many iReporters who once smoked told CNN they were aware that smoking was an expensive habit with risks such as emphysema and cancer, but they couldn't quit.

CNN: Breaking up is hard to do, especially with your cigarette