5. Pierre Omidyar

At 50 years old, Omidyar is the youngest billionaire on this list, but that doesn't make him any less powerful or generous. The Paris-born Iranian-American businessman is the co-founder and former chairman of eBay, the popular internet auction site. From a young age onwards, Omidyar was a computer enthusiast. He later graduated with computer science degree from Tufts University in Medford/Somerville, Massachusetts, and worked for a few computer companies before starting his own business venture, a pen-based computer startup called Ink Development.