As a business owner, you have to look at it from the Law's standpoint, and from your clientele standpoint. I own a bowling center that was forced to go Non-Smoking by the county back in 08/08. Luckily many other bowling centers across the country had to deal with the change long before me, and I knew once the smoking ban hit, to quickly change my marketing to target "Family Friendly Fun." Because of this my business took a very small hit at first, and I'm now actually more profitable b/c of the smoking ban.
That said, I am/was a smoker and I'm new to the vaping game (as you can tell by my post count) and was actually turned onto it by a customer that came in and tried to puff without asking. Immediately I had 20 angry parents in front of my control counter complaining about the "Filthy Smoker" down at the other end. When I went down and asked him to take it outside, he proceeded to try and fill me in that it wasn't really smoking and blah blah blah, you guys know the rest. Still I had to run him outside or risk losing 20-40 customers on the spot and their future business. I went outside and talked with the guy for awhile and he explained the device to me and gave me a couple of websites to check it out on.
I'm now a happy e-cig vaporer (still don't have your guy's lingo down yet) and have since bought the device for all of my employees that still smoke so they can get their fix without having to take an obscene break (b/c our County non-smoking ban prevents my employees from smoking on my property, they have to get in their car and take a ride to get a cig, it's ridiculous). That being said, there's still no way I could allow it inside my establishment. The general public don't know what it is, and quite frankly just think you are smoking. Until there is more public knowledge about e-cigs, you just aren't going to be welcomed. Even if the owner allows it, you're still going to present them with a constant headache of misinformed angry customers...