Manda, I never smoked fags (although I've done many bad things in my life), and I think it's a disgusting habit. Even more annoying so, when you think that most people start smoking at young age just to impress classmates or feel more accepted in a group. Most people I know who stopped smoking, such as my grandad, my father and a dear uncle, stopped overnight with no help of any chemicals, purely because they've seen how awful it was to witness more than one person dying from lung cancer in our family, and they started developing symptoms that made them believe they were heading the same way.
For men it is even worse, because apart from various cancers and heart diseases, smoking is also one of the main causes of impotence and although young men don't seem to care less, when it hits you it's normally too late.
From what I heard, one of the most efficient ways to quit smoking is hypnosis, but you need to believe in this and find a very good professional. I have a friend who stopped smoking right after stepping out of a hypnosis session, and never lit a fag again. It will not only be a great thing for him health wise but financially it you take into consideration he used to smoke more than a pack a day.
If you don't believe in any of that and want to go for a chemical approach, there is a new drug in the market called Rimonabant which is believed to be the most effective weapon against tobacco addiction and has just been released into the market under the name of Acomplia.
If you wanna read more about it, go to
http://en.wikipedia.org/wiki/Acomplia
It's not cheap I think it cost around £ 100.00 for a months treatment, and it's
originally developed as a anti-obesity drug, so expect to lose wait as well.
If you decide to buy it, you'll have to google this name and you'll see loads of shops selling it online.
Good luck.