What's scary about that Blackcatter? If there are sizeable amounts of money, you just pay them in to the bank and they'll change them. It it's just small change, pass them across to some charity which is collecting it with a view to doing the same.

Up till the end of February there shouldn't be any hassles at all about changing the money. After that it shouldn't be hard up until the end of the year - for example Bureaux de Change in British Airports will change currencies up till December 31st. After that itll be harder, but there'll be arrangements to allow for hoards of the old banknotes turning up in Granny's old rocking chair.