I smoked for about 4 years too and have been smoke free for about 1.5 years now. I quit cold turkey. I set a date about a month ahead of time for the date that I would actualy quit. I smoked like a fein (sp?) for that next month, so much that I was sick of it when I got to my quit date. It was not easy though. For about a month after my quit date I was the most irritated, miserable person you would ever meet and every little thing set me off.
It's definitely not easy but now I dont even crave a cigarette, which I never thought I would be able to say! I feel so much better now!