Sitting in Michael's Lap
I agree with Sharon - your average teenager thinks 30 is ancient, and 50 is forever away ... "who cares if I'll have lung cancer when I'm drooling on myself and wearing adult diapers?"
(ducks the tomatoes from the 50+ crowd)
I think focusing on the "cigarettes aren't cool" aspect is working. Of course, the rising cost of cigarettes doesn't hurt either - as a non-smoker I'd be thrilled to see em at $20 a pack or more - let the rich bastards kill themselves off if they want to, they can afford to buy new lungs on the black market.
In my youth, and even in my 30-year-old decrepitude *winks*, the biggest turn off for me about cigarettes was the yuck factor. They smell awful and taste worse!