I have never used an e-cigarette (obviously) but have a friend who told me she was "Taking one day at a time to be a non-smoker."
From the first day, she began using the e-cig. in place of her normal cigs, but appeared to be sucking on it so desperately! She said it did not replace a real cigarette. I felt it was defeating the whole point. NRT's are better, as Ashley says, giving you a gradual reduction in nicotine.
Saying that, I have another friend, who has Emphysema, and quit smoking using the inhalator. She quit before me in 2004, yet continues sucking madly on the little white tube! In fact, I suspect she gets more nicotine from it than she ever got from smoking. At least she does not have the tar and smoke any more!
Quitting is more than replacing the nicotine... In my opinion, quitting involves a planned approach to change a lifetime habit, including physical addiction, psychological addiction and habitual behaviour. I used NRT's and found the gradual weaning to be the best way, but everyone does it his own way. I did have a plastic cigarette (like a pacifier/dummy) stuck in my mouth for a few weeks, or a straw or a pen! The use of a crutch does help, but not to the detriment of health.
I always say..." Whatever it takes, just don't smoke!"
Love Lolly.