Hi, I've been using one of these for months and have not smoked a real cigarette since the beginning of Feb.
The main issue seems to be lack of testing and you can read ten different articles all with different outcomes.... try here for a world wide opinion...
http://en.wikipedia.o.../Electronic_cigarette
I was very breathless for a while and thought it may have been own to the e-cigs but that is easing off now and I for one shall be carrying on with them till I get bored lol
Lisa x