T. Boone Pickens

Fred Prouser/Reuters

T. Boone Pickens

Founder, Mesa Power
AGE: 80

Pickens is having the time of his life. His BP Capital, an energy trading firm, has made him a billionaire. He's invested in water rights, wind power, and natural gas. He wants to lessen America's dependency on oil. And his autobiography, The First Billion Is the Hardest, appears this fall. Hard to believe that 10 years ago, he had lost control of his oil company and was going through a nasty divorce.
Li Ka-shing
Chairman, Cheung Kong Holdings , Hutchison Whampoa
AGE: 80

Li shows no signs of slowing down. Known for well-timed asset flipping, he has constructed a global empire of ports, telecoms, power generation, property, and retail. Worth more than $18 billion, Li is one of Asia's most prominent philanthropists and a benefactor of Shantou University in China. Li says he plans to donate one third of his fortune to charity.