DAVOS, SWITZERLAND - JANUARY 24:  Microsoft Chairman Bill Gates attends the second day of the World Economic Forum January 24, 2008 in Davos, Switzerland. Some of the World's top business people, heads of state and representatives of NGOs will meet at the forum until Sunday. Getty Images logo Getty Images 49 months ago

DAVOS, SWITZERLAND - JANUARY 24: Microsoft Chairman Bill Gates attends the second day of the World Economic Forum January 24, 2008 in Davos, Switzerland. Some of the World's top business people, heads of state and representatives of NGOs will meet at the forum until Sunday.