I stopped a couple of months ago using Allen Carr's easy way to stop smoking -
Literary genius it isn't, and it certainly doesn't hit you with the traditional 'you'll get cancer' horror stories but what it does do is gradually alter your perception of cigarettes. It's sort of based on positive reinforcement with alot of 'duh how could I be so damn stupid'.
I'd stopped a couple of times before - the longest for 6 months when my mum died of cancer but that didn't stop me from starting again when the going got tough. I still smoke as much dope as I did before but I haven't touched a cigarette for two months and haven't even considered it when bored which is the toughest time for me. This has by far been my easiest and most successful stopping attempt.
Try it, thousands over here have used it successfully and what do you have to lose? It's about the price of two packets of marlboro, in fact less than that when you look at what we pay for ciggies over here.