I've got a bunch of niche travel websites about gambling related destinations (Las Vegas, Atlantic City etc). I've found that when I'm visiting any of these places I'm usually searching for phone numbers for restaurants, show tickets and what not using my Treo. I've thought about building a mobile versions for years but lack of ROI on these have been a barrier for entry. Has anyone had any experience with monetizing sites built for mobile devices - ie advertising, sponsorships or ecommerce? Is this still too new of a platform to attempt to monetizing advertising supported content? I'd love to hear any success stories for mobile website owners and tips for ad partners would be greatly appreciated.