Last year, in the aftermath of the Asian financial crisis, the trend in global policy regarding exchange rate regimes was clear.

The usual model of fixed-but-adjustable regimes, usually pegged to the US dollar, which had characterised east Asian emerging markets, was increasingly regarded as anathema. Key policy makers, including the US Treasury, were trying to persuade countries to adopt systems at either end of the fixed-to-floating spectrum.

Either a form of automatic permanent fixing, such as a currency board, or a free float with the direction of currencies determined by the markets, were the preferred options. In the immediate aftermath of the crisis, most stricken countries - by necessity as much as by design - adopted floats with varying degrees of informal intervention.

That situation has changed little. Over the last six months, there have been a few tentative moves towards the most permanent form of currency fixing - the forming of new currency blocs. But, with most emerging market economies and currencies relatively stable, there appears to be little incentive for radical change. Meanwhile, as the euro has slumped ever lower against the dollar and yen, more attention has been paid to the renewed possibility of some co-ordinated action to prop up the ailing European currency.

In east Asia, frequently seen as the test-bed for currency arrangements, some interest has recently been created by plans for new swap arrangements between 13 of the region's countries. In May, these countries - including the heavy-hitters, in central bank terms, of Japan and China - agreed to set up a system of bilateral swaps with the aim of reducing currency volatility.

Some observers have talked up this development as the first sign of a new approach to co-operation among east Asian countries. Martin Hufner, the chief economist at HypoVereins bank, says this resembles the first movements towards European monetary union in the early 1970s, including the exchange rate "snake" and the European monetary system. "The Asian countries have even started talking about fixed exchange rate bands - precisely the dialogue that led Europeans to the common currency," he says. "Given that it took 25 years for Europe's early experiments in taming foreign exchange markets to lead to the euro, is a common Asian currency so unthinkable?"

But, for the moment, most analysts regard the currency swap arrangements as more a form of political symbolism than economic substance. "The capital outflows from the region at the moment reflect repayment of debt more than capital flight," says Gene Frieda, head of emerging market research at the economic consultancy 4Cast. "In those circumstances, are other countries really going to come in and prop up a falling currency? The likelihood of these arrangements being used on any serious scale is very small."

At the moment, he says, most emerging market Asian countries, including Indonesia, Thailand, Singapore and South Korea, continue to intervene informally in their own currencies when required - ostensibly to smooth market fluctuations, but often with the apparent aim of maintaining a level for the currency.

In Latin America, there is a greater variety of arrangements which provide natural experiments for determining the optimal exchange rate regime. Of particular interest to those in the region has been the relative performance of Argentina, which stuck with its currency board, and Brazil, which was blasted out of its crawling peg system and has since followed a reasonably non-interventionist float. Meanwhile, Ecuador has provided one of the few concrete examples of the often-discussed policy of dollarisation.

Mr Frieda says that of these options, the float seems to most observers to have been the most successful so far. The old Latin American problem of uncontrollably rising inflation and a falling currency has yet to materialise.

Meanwhile, the attractiveness of the currency board has diminished as policymakers have realised it does not prevent investors marking down local currency bonds by adding on a risk premium, Mr Frieda says, while Ecuador's policy of dollarisation was adopted mainly out of desperation. "What has become clear is that a floating currency can work as long as the right domestic policies, particularly with regard to the fiscal position, are in place," he says. "With free floats working relatively well for the moment, there is no real momentum behind a move towards region-wide dollarisation."

Meanwhile, although the large industrialised economies seem as far away as ever from instituting some permanent formal mechanism for managing their currencies, speculation has again risen that there will be some medium-term joint action to prop up the euro.

As it continues to fall against the dollar and yen, the euro looks more and more undervalued. The European Central Bank has refused to panic publicly about its level, but officials have indicated that the currency clearly does not reflect fundamentals. Japanese officials have said that they would support joint intervention to push the currency higher. But, as ever, the prospect of a new plaza-style accord to realign currencies depends on the attitude of the one country needed to give the move some real credibility - the US.