> EUA was exchanged 1:1 for ECU, then 1:1 for EUR, so that's a nice continuation.

Interesting, I didn't know that. We did something similar here in Brazil to get rid of the hyperinflation: the Real (which started at 1:1 with the USD) was preceded by the URV, an accounting measure which was used to denominate all prices; during that time, the prices continued to inflate in the former currency, but were mostly fixed in URV, so when the currency changed from Cruzeiro Real to Real (at 1:1 with the URV), the prices stopped inflating so much. Of course, that was not the only thing the Plano Real did to get rid of the hyperinflation, but it got rid of an important "inertial" component of the inflation, in which prices inflated daily because they had always inflated daily.