The world thinks of microfinance as a tool to lift its poorest from grinding poverty. But in an age of pricey fuel and shrinking credit, the entrepreneurial movement that began in Bangladesh is taking off in the richest country of all.

Nobel prize winner Muhammad Yunus opened 11 branches of his Grameen Bank in New York City this spring, more than 30 years after he revolutionised foreign aid by delivering the first microloan to a group of rural Asian villagers.

If Yunus is the father of microfinance, his US offspring already are maturing quite nicely. The spectre of recession, combined with a diverse array of lending models, is sparking a new demand in America for small loans and business counselling.

"Our vendors report a dramatic increase in microloan applications over the past year," Amy McKenna Luz, who represents nearly 500 microfinanciers as president of the Association for Enterprise Opportunity, said. "They say it's a direct result of the banking crisis."

Luz sees her member groups as rescue workers for small businesses, nurturing economic growth and revival even in the direst circumstances. When the owner of Tomas Trucking in New York needed to ship more products to absorb the cost of diesel, a bank could not provide the cash infusion needed to buy a new vehicle and save the company. Microfinance saved the day.

Why has the spotlight shone so brightly on Grameen and not on its industrialised cousins? The answer may be culture.

Almost anyone can send a few dollars to Asia that can feed a family for weeks, thanks to Kiva and other groups that turn ordinary Americans into microlenders. But sending a few thousand dollars to a rural Pennsylvania craftsman is more difficult.

Micro Business Development Corporation, led by Denver lender Kersten Hostetter, has created thousands of jobs and boosted the local economy by more than $15m. Still, Hostetter is so keen for more investment that she has written a unique job ad seeking a celebrity spokesman for US microfinance.

"We're the bridge between poverty alleviation and economic development, the guardians of the middle class," Hostetter said. "We didn't brand ourselves initially because there wasn't a need for it."

Now the need has arisen, partly due to the arrival of Grameen America. Thanks to its Nobel, the bank does not have to rely on Natalie Portman - Hollywood spokeswoman for the international microlender Finca - to create universal appeal.

For its pilot programme, Grameen has targeted immigrant enclaves. There, the "peer lending" model of requiring clients to attend weekly meetings and monitor each other's repayments is most likely to succeed.

In more traditional communities, however, microlenders like Galen Gondolfi have had to perform a more complex version of the Bengali approach.

One client came to Gondolfi, a senior loan counsellor at Justine Petersen in St Louis, was persuaded to pull equity out of her home to expand her business during flush economic times. As global markets fell, her mortgage interest rate went from 6% to 14%, new contracts dried up, and she left stacks of bills unpaid.

Gondolfi performed "a triage of sorts", he recalled, "stopping the bleeding" on her mortgage by negotiating a new rate with her subprime lender while using the house as collateral for an infusion of cash to her company.

Microfinance is not just for the developing world, Gondolfi said: "It's also for the post-developed world. I'm talking about rust belt cities, about urban neighbourhoods I work with that are essentially post-apocalyptic."

Microfinance is also not just for the political right or left. Conservatives have embraced it as an alternative to direct foreign aid that can resemble a handout, while Hillary Clinton helped her husband bring Yunus's ideas to Arkansas in the 1980s.

The failure of the Clintons' microlending effort, called the Good Faith Fund, has tempered the enthusiasm for a similar grassroots push during the current economic slowdown. The conventional wisdom says Good Faith proved that microfinance could not work in America.

Richard Taub, a sociology professor at the University of Chicago who helped with the Arkansas programme, called it "kind of a bummer".

"The cost of the administrative work was very, very high," he said. "We used to joke that it cost $10,000 to make an $8,000 loan."

Taub was also sceptical of marketing microfinance to immigrants who already lend in small amounts to one another, likening Grameen America to "selling coal to Newcastle".

In fact, New York already has a microfinance powerhouse. The local outlet of US-based Accion, headed by Gina Harman, has generated 11,000 new businesses and given $77m in loans since its founding in 1991.

Harman sees plenty of room for Accion and Grameen to work together in broadening the scope of US microlending. Her only worry is that the entire movement could be judged on the success or failure of Yunus's new banks.

"Unfortunately, we're not microfinance rock stars," Harman said. "Right now we're doing a lot of parrying to try and defend an established track record. It works."

The way it works is usually with interest rates of about 12%, higher than bank loans but far lower than the average US credit card. The third alternative for struggling small businessmen are so-called "payday lenders", who charge up to 600% interest and are barred from operating in several states.

Harman said Accion is also encountering more new clients who are desperately fleeing a debt to loan sharks. "It's a very frightening circumstance," she added.

With the economic outlook keeping large banks on the defensive, the number of struggling Americans not getting help is likely to only increase. Demand is already too high for some established microlenders to serve everyone.

"The outsourcing of components of a company, downsizing, the loss of middle-class jobs - all of those are push factors" forcing clients into the industry, Elaine Edgcomb, director of microenterprise research at the Aspen Institute think-tank, said.

Other "pull factors" luring clients also are on the rise, chiefly the stunning growth of immigration in the US.

Given such challenges, microfinanciers are not waiting for their Angelina Jolie to emerge from the wings. McKenna Luz's group will host microlenders from around the country at a summit in California later this month.

Governor Arnold Schwarzenegger and his wife Maria Shriver are slated to attend, and she is hoping that Nobel winner Yunus can speak as well. "It's like Tony Blair trying to make an appearance," McKenna Luz said.