Employers have recently tried every carrot they can think of — including cash incentives and iPods — to persuade employees to quit smoking. Now some are trying the stick. Pointing to rising health costs and the oversized proportion of insurance claims attributed to smokers, some employers in California and around the country are refusing to hire applicants who smoke and, sometimes, firing employees who refuse to quit. "Employers are realizing the majority of health costs are spent on a small minority of workers," says Bill Whitmer, chief executive of the Health Enhancement Research Organization, an employer and healthcare coalition in...