I tried to quit cold turkey, but found that I wanted to kill every human being with which I came into contact (as my job is adversarial by nature, that was not a good thing

). I went on the patch and the urge to kill lessened a great deal. I didn't smoke anything for two years.
Unfortunately, I live in the City within walking distance of my favorite bars and restaurants and, alas, I started smoking again, but only when I go out (which is much too frequently) -- most of my friends do the same, which makes it difficult not to light up after a few beers.
In my experience two things keep you smoking, nicotine addition and the social/functional habit. The patch, at least for me, curbed the addiction a great deal; unfortunately, environment and association are keeping me in Marlboro Lights right now.
It's easier to quit when you under go an evironmental change or disassociations. So, if your about to graduate, switch jobs, move to a new location, etc., you might seize one of those opportunities. My wife and I are moving to the burbs soon, and I'll take that opportunity to lay off the social smoking.