Agreed with Gong01 - I've found mindfulness the best for breaking addictions. Eckhart Tolle recommends taking a few mindful breaths whenever you feel the urge. Acknowledge the feeling, feel the feeling directly, breath into the feeling. When I got cravings, for instance, my mouth and neck had this funny, sore, thirsty feeling and I got super restless. Instead of thinking about it "Oh I need a puff NOW!", I breathed, and felt that feeling directly - just feeling the soreness and thirstiness. At this point, I'm going to break convention - you shouldn't force yourself to stop. If after a few breaths you still need one, then have one. But after a while it will die out.
Of course you could try the other thing - smoke non-stop for as long as you can. Even when you don't feel like smoking, when you are coughing, wheezing, etc, keep smoking. After a weekend, you probably won't feel like it anymore
Warning: Second part was half joke (so if something bad happens don't blame me) It half worked for me, though - but I wasn't a heavy smoker.