The Bill & Melinda Gates Foundation, the world's largest philanthropic organization, has a singular objective: improve the lives of people in poor countries. Historically, the foundation has given away money, much of it to fight infectious diseases. Now it has a new strategy: invest in technologies that can make goods and services affordable to the poor. Bloomberg's Erik Schatzker sat down with Bill Gates and traveled to Bangladesh to see how one of those investments, bKash, is transforming finance. (Source: Bloomberg)