Non-smoker. Never smoked, can't imagine I ever will. Considering my respiratory distress around second-hand smoke (and discomfort around the smell -- the first half-hour of my recent airplane flight was pretty unpleasant, until my seat-mate's reek wore off (or I acclimated?)), I'd have to be nuts. When my allergies are in high gear, the smoke makes me cough and wheeze; when my allergies haven't been triggered lately, it's more of a mild irritant.
If you have smoked recently and are sharing an elevator with me, I will know. (I will
also know if you doused yourself with perfume or cologne, but that's another story.

) I was thrilled when airlines stopped allowing smoking (sadly, the smoke does not STAY in the smoking section); and even more happy when California law changed to disallow smoking in restaurants.