Hypnosis is a practice that puts people into an altered state of mind that some believe makes them far more susceptible to suggestion. You can be treated by a hypnotherapist in an office setting, and you can buy smoking-cessation-by-hypnosis books and CDs to be used at home.
There are many who believe that hypnosis is an effective means of smoking cessation. Some studies have suggested that hypnotherapy can be either as effective as, or substantially more effective than, NRTs and other smoking cessation techniques.
However, the effectiveness of hypnosis for smoking cessation has not been confirmed by the broader medical community. If you are interested, ask your doctor if he or she can recommend a good hypnotherapist for you.