Almost a different nation, but being so remote, I presume there's no serious Tasmanian independence movement?
We never changed to the Euro (probably a wise move for us) and stuck with the pound which may have been an experiment too far for some of the countries involved, though it was beneficial for the major players in mainland Europe when travelling and trading between adjoining nations. Also meant that if I was travelling abroad for work, I only had to get a new stock of Euros from time to time, rather than keep changing money Francs, Deutchmarks, Guilders, Krone etc. and back again (always at a loss thanks to the Bureau de Change exchange and commission rates).