To tout CI Host, his Texas-based Web-hosting company, Christopher Faulkner paid a man $7,000 to tattoo its logo on the back of his head. Faulkner found the guy, a salesman for nuclear power plants, on eBay; he went under the needle in March.

It turns out a growing number of companies are using the human body as a canvas for walking, talking advertisements. Cunning Stunts Communications, a marketing firm in the United Kingdom, pays students to display temporary tattoos of logos on their foreheads for at least three hours daily in public. And Cleveland-based ad firm Marcus Thomas recently hired young Bostonians to shave tire tread into their hair to promote Dunlop Tires. The "Tread Heads"--who frequented bars and sporting events as part of the promo--were given some cash, a chance to win a trip to France, and free gas cards. "We really wanted to communicate the edginess of our product--speed performance as well as extreme performance," explains Dunlop's Rozmond Kennon, who plans to bring the campaign to Las Vegas and other U.S. cities in 2004.

Such guerrilla gimmicks tend to work for lesser-known companies with fewer marketing dollars, but "if you pick a concept that's different from your brand, you can run into problems," says Clayton Tolley, of identity consultancy Addison Whitney in Charlotte, N.C. In other words, an edgy tattoo campaign might be more apropos for a microbrewery or a snowboard maker.