According to the smoke ban laws, it is legal to vape pretty much anywhere you want. You can whip out your electronic cigarette in your car, in a bar, in a classroom, in a theater, in outer space, and even in airplanes (except for Southwest which allows you to take them on planes but not use them). There simply is no legal language that explicitly says that you cant vape places. Anywhere besides New Jersey, New Hampshire, New York and Pennsylvania does not have laws that prohibit e-cig usage and sale. And to me, this is completely logical. Vapor does not project second hand smoke and there is no lingering or offensive odor, nor a fire or burn hazard.
But does this mean that you should go to a club and start blowing fat plumes of vapor in peoples faces? Definitely not. If a security sees you smoking something out of a strange device, he will most likely think you are smoking weed. This has happened to me on numerous occasions. When I explain to him its merely an electronic cigarette, they always back off.
I personally dont believe people should be vaping conspicioulsy in public establishments in general. Its simply obnoxious. It will annoy people. As vapers, we dont want to be considered annoying people.
In short, I think that we should all feel free to vape pretty much anywhere we want, but do so discretely. I take ghost hits on the BART (The bay areas subway system), in bars, in clubs, restaurants pretty much anywhere, but I do so discretely and respectfully.
And theres another plus side to forcing yourself to vape discretely: when you step outside you will no longer have to limit yourself and it will allow you to have that fresh air break that you used to take when you smoked analogs.