Stewart Butterfield is the co-founder of Flickr, the popular photosharing website. Named by Time magazine as One of the 100 Most Influential People in the World, Butterfield is a founding father of participatory media. Alongside the giants of social media -- Facebook, MySpace and YouTube -- Flickr has produced a seismic shift in the way people use technology in their everyday lives. Newsweek calls it "a poster child on how a well-executed Net effort can make big changes in people's habits."
