I do not smoke (although I have tried it several times, and several types), and at first it was really annoying to be talking to people, or to be surrounded by people that were smoking. As I grew older, I learnt how to just ignore the smoke, I tend to ask my friends to turn around or something. But if I'm stuck with someone I don't know, I just try to breath as less as I can, to inhale the less.
It doesn't bug me that much now though, I can't really say why.
Although I respect their choice of smoking, I disagree on the fact that they are allowed to ruin everyone's life, but then again, smoking outside doesn't cause much harm. Smoking in a restaurant is much much nastier and I am for the set up of regulations in public places. Here in France, smoking in trains has been strictly prohibited not so long ago, which is a VERY good thing.