The possibility of Greece exiting the euro is met with abject terror from economists worldwide. But if the struggling nation were to pull the plug on the single currency and decide to return to the drachma, economics aside, the process would be startlingly simple.

"Converting national payment systems is of course not easy, but it is probably easier than one might think," says an analyst from a central bank in Europe. "It can be less complex than the introduction of the euro to go back to the