As a smoker I agree that it should not be allowed anywhere in the cabin. And I remember the days when we could light up in the rear of the cabin. Now, I don't even think about cigarettes in flight.
Many airports have smoking lounges skyside which are a nice convenience and allow you to get a few in before boarding. Surprisingly, some of the airport bars here in the states still allow it. Until about a year ago the UAL Red Carpet Lounge at O'Hare had one. Now on my layovers there (usually twice a week) I go outside. Then, I have to come back through security. Everytime I do it I can't help but think how many of us there are clogging up an already overtaxed security line just for this reason. If they had the smoking room this wouldn't be a problem.