(FORTUNE Small Business) – Like the beat poets, Wyoming resort marketer Jeff Heilbrun found his inspiration on the road. In February 2003, Heilbrun was driving along I-80 to Cheyenne when he had an epiphany: All those truck mudflaps sporting industry names such as Fruehauf--or the reclining-nude silhouette known as the Mudflap Madonna--were potential ad platforms. So Heilbrun, 46, and his brother Doug formed FlapMedia, which for about $75 a month per trailer lets advertisers place a short message in the one place drivers can't ignore. "You can't turn the page or get up for a beer," says Heilbrun. FlapMedia targets corporate truck fleets, whose owners are happy to get free mudflaps (not to mention a cut of the advertising revenue), and last July the company rolled out its first sale: 300 trucks owned by Central Refrigerated Services, based in West Valley City, Utah, touting WyomingTourism.org. But what about the Mudflap Madonna? "She'll be around for a long time," predicts Heilbrun. --I.M.