His perhaps-surprising conclusion: Government subsidies for the rural poor often make things worse.

Instead, Polak teaches families and farmers - many of whom live on a dollar a day and own perhaps an acre of land - how to increase crop yields with simple technologies, such as cheap, foot-operated water pumps and inexpensive drip hoses for irrigation.

A San Francisco man who is credited with changing the lives of thousands of farmers in Africa with his irrigation pumps has won the $100,000 Lemelson-MIT Award for Sustainability.

Martin Fisher is co-founder and chief executive of the San Francisco-based non-profit KickStart, which has developed and marketed low-cost, human-powered pumps that allow farmers to boost the productivity of their land -- and increase their earnings.

Rather than simply giving the pumps away, KickStart has worked with wholesalers and retailers to market the pumps, with the idea of someday creating a self-sustaining market for them.

NEW YORK (Fortune) -- "Technology is making more changes in our way of life than ever in human history," says Muhammad Yunus. "The way the Internet and the mobile phone are spreading, you cannot compare with any technology of the past." Yunus is known for his visionary leadership in microfinance and helping the poor. He and the Grameen Bank he founded won the Nobel Peace Prize in 2006. Now he wants to see the tech industry work more explicitly to empower the poor.

Yunus has just been awarded the James C. Morgan Global Humanitarian Award by the Tech Museum of Innovation. The Tech Awards are to be presented in San Jose in November and are funded by chip-equipment maker Applied Materials (AMAT, Fortune 500). In addition to the Morgan Award, they annually recognize 25 people for visionary uses of technology to solve the world's problems.

Yunus is an impatient man. Perhaps that's why he has accomplished so much. In addition to the micro-lending bank, Yunos has created a variety of other businesses under the Grameen family of companies. It has helped create about 25 other companies or institutions in Bangladesh and around the world, including fish-farming and knitwear businesses and a provider of health-care services. But most of Grameen's businesses have something to do with tech: Bangladesh's largest cell phone company (which is also its largest private employer), an Internet service provider, an electronics manufacturer, a business IT consultant and a developer of high-tech office buildings.

In 1985, a young mechanical engineer named Martin Fisher traveled to Kenya on a Fulbright scholarship. Fisher planned to stay for a few months, putting his degree to meaningful use working on projects for the rural poor, but he soon found himself absorbed in the world of international development. Months turned into years as Fisher worked on rural water projects with communal wells, helped women's groups start small businesses and helped produce farm equipment to give to farmers.

But after a few years, Fisher took a hard look at the work he and his colleagues had done and found it disappointing. Although the projects were successful in the short-term, they turned out to be "totally unsustainable," Fisher explained. "We would walk away from these things and they would collapse." Communal pumps would break, and no one would repair them. Efforts to provide people with things that they desperately needed - water pumps, homes, farm equipment - were simply temporary fixes, no matter how inexpensive, simple or well-intentioned.

What, he wondered, did poor people really need? Rather than beginning yet another attempt at a charitable solution, Fisher put this question directly to the poor, trying to determine what would be most useful to them.

What he found surprised him. Designing products to help the poor, Fisher discovered, was in some ways a through-the-looking-glass experience, a reversal of traditional assumptions. Where design efforts for the poor often focused on saving them time and labor, poor people had both time and labor in abundance. Where design traditionally emphasized quality and durability, the extremely poor, whose lives and needs often changed unexpectedly, preferred affordability. Above all, Fisher found, the innovations that had the most impact were often those that helped individuals earn money, not those that solved quality-of-life issues or were the basis of a community project.

Today, two decades later, Fisher and a small but growing contingent of designers, engineers, businesspeople and nonprofit workers are pioneering a new approach to international development: designing and distributing affordable, useful and in many cases, income-producing products to the extremely poor. Garnering national attention with the recent exhibit, "Design for the Other 90%," at the Cooper-Hewitt Museum in New York City, the nascent movement is not simply a design revolution, or an ambitious business plan, but a combination of both. It has also begun to change some of the basic assumptions about design, business and solutions to poverty.