Chairman, One Laptop Per ChildRank: 29Why he matters: The MIT Media Lab co-founder's nonprofit group, One Laptop Per Child, has created an inexpensive notebook computer for children in developing nations. The goal is to make a machine that sells for $100.
For now, however, the first laptops will cost $175, and even then, One Laptop Per Child needs orders for 3 million units to get started. Though cheap, the Linux machines come with free e-books, learning software, and a Web browser. A windup crank permits use off the electric grid, and rabbit-ear antennas create long-distance Wi-Fi mesh networks so entire villages can share a single Internet connection.
Meet 50 Who Matter winner Gina Bianchini. Her site, Ning, lets anyone be a social networking mogul. (more) 
