This article is from the Europe FAQ, by Yves Bellefeuille email@example.com with help from Martin Rich M.G.Rich@city.ac.uk.
It can be useful to obtain a small amount of the local currency (perhaps
$ 20 to $ 50 per traveller) before you leave. Most airports now have
cash machines, and it's doubtful whether any major airport doesn't have
one, so you can withdraw more money once you arrive.
The exception is Turkey, as mentioned above: you should try to change
money in Turkey itself.