Vast sums of money criss-cross the globe each day, as millions of migrant workers send a portion of their pay packet home.
This surging flow of funds supports one in 10 people on the planet, but the world financial crisis could slam on the brakes.
In some cases it's the workers that are now making the journey home, rather than the money they've earned, month after month, in a foreign country.
"I was in Doha, talking to a guy from Djibouti and he says he makes about $500 to $600 a month and sends about $300 to his family," says economist Dilip Ratha, the head of the World Bank team which studies these money flows, known as remittances.
"Basically, every penny he doesn't spend goes home. And I've heard the same story from Pakistani undocumented migrants in Madrid, from Bangladeshis in Austria, El Salvadorians in Washington - they basically move to send money home."