I wouldn't bother with changing any in the US. Take a fair amount of dollars, say $150, and an ATM card. The reason for taking USD is in case your bank's ATM is not accepted. Call your bank and find someone in the know and ask, but still assume your bank hoses you when you need the money. Credit cards, (preferably 0% exchange) are the way to go for most transactions. As said before, you won't be hit with a per transaction fee (from the dispensing bank) so don't go overboard on taking out cash. If I'm in the Euro zone for a week say, I'd take no more than 200 euros to start, use the CC as much as possible and see how fast cash disappears .
One other note. Kill your leftover local currency with the hotel at check out. Figure just how much you will need to get you to the airport and home, than use what cash you have to help settle up your bill. Hotels are very good at letting you pay in cash and the balance on the CC.

Bon Vonage

One more thing. Take at least two credit cards and call both before you go and tell them you will be traveling overseas.