There was never a need for a combined currency all over Europe
And as Tim points out, it was never going to work and isn't working now.
What was needed was something that allowed a single currency to be *spent* all over Europe, at the exchange rate of the day - if only to avoid the idiocy of travelling across the continent with fifteen different currencies in your pocket, getting shafted coming and going on exchange rates.
Even an international debit/credit card doesn't work properly because it's not accepted everywhere.
But that said, I do think the common market was a good idea and I think the right to move and live in any of the countries a good idea - though there are obvious issues (for example, the one that gets everybody agitated - use of local services by immigrants: just require their home nation to pay their social security/hospital bills/unemployment benefit/school costs/whatever and let them pay their taxes back home. We'd still get their VAT...)
Biting the hand that feeds IT
