Our series continues today with a look at technology. Charles Fishman, author of The Big Thirst, has seen plenty of water filters that fail and he talks about the "people factor." Physicist Ashok Gadgil grew up in India where several of his baby cousins died from bad drinking water. He came up with a kind of filter that's cheap and easy to repair, and he's hopeful about the success. It means millions of people now have clean water to drink.

Ned Breslin has spent twenty years trying to bring clean water to people in the developing world. While many people who do that kind of work tout their successes, Ned likes to talk about his failures. He says each one has taught him a little more about the magnitude of the challenges, and what it will take to make a difference. Photo: Ned's picture of Dona Fatima, the woman he met in Mozambique. 

Most home builders in Florida have been struggling to get by, but Steve Ellis' construction business is thriving. Steve renovates older, smaller houses to be cooler and more energy efficient. And in the process he's made green living affordable. Steve tells Dick Gordon how the values his father taught him shaped both his business plan, and Steve's plans for his own new green vacation home.Also in this episodes: tubes tied at 27. And an update on our story of shark finning.