I hate second-hand smoke, so I think it's excellent that people are using electronic cigarettes to help them quit smoking.
In recent research Action on Smoking and Health surveyed smokers and found that the number of people who have tried electronic cigarettes is now three times higher than it was in 2010. Most use them to cut down their smoking.
E-cigarettes vaporise nicotine instead of burning tobacco like normal cigarettes. We still don't know the health effects, so I hope they won't make people think smoking is OK!