Gonna start off by stating that I am a smoker so I'm biased. I'm all for there being no smoking areas and such but come on if a person wants to have a smoke let them. It's the same reason for drinking and eating fast food, that stuff isn't healthy for you but we have the choice to consume it if we want. Then the whole argument for the toxins from second hand isn't a great enough reason for it either. From cars, factory's, even burning wood releases toxins into the air at a much greater rate than all the smokers in the world. Again I am biased on this subject.
You can ban anything you want people will still find ways to use it (i.e. alcohol prohibition, marijuana). I can say that it hasn't really worked out in the US that well.
People need to be responsible, the world has more than enough nanny states as it is.