It's fine to help the developing world, but first you have to know what it needs. Amy Smith does.
An engineer and the founder of MIT's innovative D-Lab, Smith, 47, is a former Peace Corps volunteer who spent parts of her childhood in India and Botswana. She's the creator of a hammer mill that converts grain to flour and an incubator that does not require electricity. Her design philosophy is elegant: create simple machines that meet particular needs and then build them locally.
Smith is also a teacher, taking kids to Haiti and Africa, where they design pumps, bicycle parts and other gear people need. Her machines are one of her gifts to the world; the students she trains will be an even more enduring one.
Pentland is a professor in the MIT Media Lab and the director of its entrepreneurship program