The problem with those is that you blow the puff of "smoke" when the cigarette is in your mouth, and then when you take the cigarette away, there's nothing. Which is not how cigarettes work.
They make very realistic e-cigarettes that only light up when you inhale, just like an actual cigarette. It does have the problem of not burning down and yes, they do make that unfortunate "clunk" in ashtrays if you don't set them down ever-so-gingerly. But I prefer that to puff cigarettes and especially to the noxious herbal ones.
