One day, Winston Duncan,11, asked his mom to take him to Africa to see wild animals, but in August, when they went to Botswana, Zimbabwe, Zambia, and Swaziland, what Winston noticed more were the people.

"I was just looking out the window. I saw all these people," Winston recalls. "They were walking. They didn't look well. Some people looked sick. I thought, 'How can I help them, because this is a hard sight to see? So, then I thought, 'What if we got them bikes?'"

Back from his trip and back to school, Winston founded a charitable organization called Wheels to Africa. He donated his own bike for starters, and at an evening session of the local board of education, Winston requested the board's permission to collect more bikes at school. "He went in and told them what he wanted to do. And they were just dumbfounded, as was I," says Winston's mom, Dixie Duncan, who is clearly proud of her son's activism

Winston also set up an internet blog site -- a kind of online journal -- to promote his campaign. He then contacted a Washington, D.C.-based group that ships used bicycles to countries in Africa and other parts of the developing world.

Called Bikes for the World, the non-profit group was founded earlier this year by Keith Oberg, 54, an expert in international aid who had never met Winston Duncan until a few weeks ago. But Mr. Oberg got the same idea about the value of bicycles while working as an economist at the World Bank in Washington. He recently quit his World Bank job for a career in bike collection -- convinced it's a worthy and workable charity.

"I started 'Bikes for the World,' based on the belief that the bicycle can be an empowering tool for individual development and community development," he says, noting there's no mass transit in many developing countries. "People are walking. Giving them a bicycle gives them the ability to save time, to get to work or do work, to carry goods, to get to school, go from house to house weighing babies -- if you're doing a health project -- all of those things can be done much more efficiently in many cases using a bicycle."

Mr. Oberg says that several similar charitable groups have sprung up around the United States in recent years -- mainly because many Americans own bicycles that are in good condition but are seldom used.

"Bicycles have become more of a throwaway item in the United States than they were 20 years ago," he says. "People buy them. They [bikes] don't work out. They develop a small problem. The child [in the house] grows up and leaves the bike behind. Somebody is affluent -- they buy a new bike. What do you do with the old one? It sits there. It sits in the basement or the garage."

Keith Oberg gets regular visits at his Arlington, Virginia, home from people carrying bicycles -- like Terry Henry of Alexandria, Virginia. "I first e-mailed Mr. Oberg," Mr. Henry says, "then followed up with a phone call and the bicycle drop-off this afternoon. It was my son's bicycle. He used to carry my grandson around on the back. But they moved on, left the bicycle with me, and I wanted to see it put to good use."

Keith Oberg, the director of Bikes for the World, says his group has collected about 5,000 bikes this year, had them loaded in craters, and shipped in freighters to developing countries.

As for 11-year old Winston Duncan, he and his school friends did their share, standing outside in a cold school parking lot, collecting about 160 used bikes that he then turned over to Mr. Oberg's Bikes for the World.

Winston's mom says she has one worry about her son's zeal to help others: the boy will probably want a new bike, and then decide to give that one away, too.