What you need to know about e-cigarettes, post-Katherine Heigl

Movie queen Katherine Heigl smoked one. Now other alternative-seeking tobacco addicts want one. We have the lowdown on the e-cigarette: where you can get it, what you should expect to pay, what you should consider -- and why it'll save you money over regular cigarettes.

The e-cigarette industry has been expecting you. Since Heigl "lit up" her electronic cigarette on The Late Show with David Letterman, visits to e-cigarettedirect.com, which sells the Veppo brand, have increased by 10%, said Keith King, vice president of sales and marketing.

Electronic cigarettes are battery-operated, tobacco-free cigarettes that allow users to inhale vapor either with or without nicotine. The vapor is free from tar, carbon monoxide "and hundreds of carcinogens that are found in regular cigarettes," said the e-cigarettedirect.com site copy.