Hong Kong keeps its dollar stable by backing each dollar's worth of local money by one American dollar of reserves.

ECONOMIST: East Asia

OFFICIALLY, one American dollar will buy you 55 of the Zimbabwean kind.

ECONOMIST: Zimbabwe��s beans and bicycles

On Friday November 14th currency markets ground to a halt after the Zimbabwe dollar tumbled from 14 to one American dollar to 26-to-one.

ECONOMIST: Zimbabwe’s power failure | The

Hong Kong manages its exchange rate through a currency board, which holds one American dollar to back every 7.8 dollars in Hong Kong's money supply.

ECONOMIST: Hong Kong after Peregrine: Scaring the bears | The

Since Zimbabwe's inflation is a tad higher than America's, nobody wishes to surrender hard currency at the official rate of 55 Zimbabwe dollars to one American dollar.

ECONOMIST: The pros and cons of opting out of the global economy

On October 1st alone, the value of the Iranian rial declined by some 17 percent, collapsing to 34, 700 to one American dollar. (It has since reportedly fallen still further).

FORBES: The Contours of Iran's Currency Crisis

Mr Summers strongly denied one potential self-interested motive for a weaker dollar: to help the American stockmarket by improving the prospects of leading multinationals such as Intel, McDonald's, and Gillette, whose dollar profits from Europe have suffered from the weak euro.

ECONOMIST: Gambling with the mighty greenback | The

The loonie (so named for the bird on the one-dollar coin) has soared from a record low of 62.1 American cents in January 2002 to over 74 cents this week, its highest level in six years.

ECONOMIST: Canada's economy

At the Carlos III dollar-only shopping mall, one of many that have opened in Havana, windows are filled with American brands, such as Reebok, Nike and Coca-Cola, at prices unaffordable on ordinary Cuban salaries.

ECONOMIST: Cuba