Bill Gates (R), Microsoft Corp co-founder and co-chair of the Bill and Melinda Gates Foundation, laughs after he and Robin Li, founder and chief executive of Chinese search engine Baidu, put on shirts bearing the slogan: "Say No to Involuntary Smoking", during a media conference in Beijing June 11, 2011. Gates and Li signed an agreement to form an alliance between their charitable foundations called the "Alliance for Healthy China". [Photo/Agencies]