Ok, I have this idea, if us stoners that smoke cigs also, went out and bought a two foot bong (sold under the pretence that it is for tobacco use only), and started to use it in any and all public places, where smoking is permitted, to smoke tobacco of course, people would get exposed to bong hits.
That would freak em out, and its perfectly legal. In fact, thats what they're sold for. So do your part to raise awarness and smoke tobacco in your bong in public (in the bar, in the restaurant, at the park, anywhere in the open).