"Mobile will play an increasingly important role," says Wayne Ruttle, vice president of sales for Adflow Networks, a company that develops digital signage and interactive kiosks. "While consumers can already send a text message to a number listed on a billboard and have information or coupons sent to them, mobile offers lots of other possibilities."

One of these is QR codes, multidimensional bar codes that are already being used in Japanese advertising, thanks to code-reading software embedded in camera phones there. "Consumers in Japan read ads, then snap a photo of a code at the bottom of the page to get all kinds of additional information," says Vedrashko. "It's very cool."