Say you're watching TV and an ad for Chevy's Silverado pickup catches your eye. Come this fall, viewers using Google's new interactive television technology will be able to type the object of their desire into an onscreen search box and launch a YouTube GOOG video or surf over to Chevy's (FIATY) website. Advertisers foresee a new medium to get their message to consumers. "Google is going to revolutionize the way we use media," says Shattuck Groome, president of New York ad agency Gotham Direct Interactive, which buys TV ads for brands that include M&M's candy and Zappos.com (AMZN). "It's the future of advertising."