Ovation Talent Agency

His Web site has no ads, charges absurdly low fees to a small fraction of its visitors, has a ".org" domain, and employs 23 people. Yet despite its humble appearance, Craigslist racked up 14.1 million page views last December and was the 52nd most viewed site last December according to comScore Media Metrix. Newmark's Craigslist has become an addiction for many, who impulsively refresh the listings of free stuff, "rants & raves," and personal ads while shirking their day jobs. Most importantly, it has almost singlehandedly demolished the offline classified advertising business. (In the San Francisco Bay Area alone, one study found, the site drains up to $65 million annually from local newspapers' help-wanted ads.) Take that, old media!