The purpose of this study is to investigate the use of repetitive transcranial magnetic stimulation (rTMS) to block craving for cigarettes in smokers. rTMS is an investigational procedure, where a device called a "stimulator" provides electricity to a device that creates a magnetic field. This device is placed against the scalp in the front of the head so that the magnetic field is focused on an area of the brain that is thought to be involved in craving for cigarettes. rTMS is an investigational procedure so therefore being tested in research studies and is not approved by the U.S. Food and Drug Administration (FDA). Changes in magnetic fields during rTMS administration change electrical currents which may affect brain activity and function.