The people I know that have successfully quit have usually found there are two aspects, one being the physical addiction and the other the psychological aspect (having something to do with your hands, something to put in your mouth, etc).

The physical addiction goes away in about 2-3 days, but there's a period of about 2 weeks where the nicotine receptors are still somewhat active. The receptors are created when you start to smoke and *never* go away so the important thing is to know that (for most people) if you've quit for 20 years and have one or two cigarettes, you reactivate the receptors and the addiction is back full force.

What several friends have done for the psychological aspect is to keep some licorice sticks around, made from real licorice flavoring (fennel). There's something in the fennel that calms or satisfies the nicotine craving, and having the licorice sticks in your hand or in your mouth helps to substitute for the cigarette. Or so my friends have told me.

Hope that helps.