Leslie Fish, Filker extraordinaire among other skills, writes more about tobacco, and the truly crappy on-the-ground experimentation around tobacco's dangers.
Disclaimer: I do not smoke, drink, do drugs. My main drugs are books, blogs, and online games. My strongest chemical vices are sugar and caffeine in that order...I've almost kicked caffeine, and sugar is on the hit list. Furthermore, I find somewhat repugnant (really, I feel disgust) the idea of chemically tweaking your brain on anything more than an experimental basis (What's it like?). Nor do I encourage or endorse anyone else smoking, drinking, or drugging themselves. And it still seems like the wisest position to tentatively believe in the dangers of tobacco. But remember, settled science is mostly bogus.