My mother has one, and it is cool.
The "smoke" isn't as... "biting" as a normal cigarette is for me. (I smoke Camel Filters) but it definitely gets the job done when you're having a nic-fit. You can get your smoke in different strengths, flavors, and sizes. The biggest things to do is keep your battery charged and vaporizer clean. That being said, When smoking an "E-Cigarette" do not "hotbox" it... smoke it normally. The more you "hotbox" the e-cigarette, the less "smoke" you get... and I love smoke.
I've recently heard radio advertisements for the "water vapor" cigarette, which I believe to be what is called the "E-cigarette" which is a good thing, because when my mother ordered hers 2 years ago, E-Cigarettes were illegal in the USA due to noncompliance with FDA regulations... (more like the FDA wanting to suppress this technology) ...but all in all, it's good... just remember... charged battery... clean vaporizer... no hotboxing... and you're good to go.