Personally, I think it's really a good idea to have at least a small amount of the local currency on hand prior to arriving at the destination.

Since I do my banking at Fleet bank, they can get me whatever national currency I want, with sufficient notice, at same exchange rates as at an foreign ATM. Having something like $50 in cash in my pockets as I walk off the plane makes me feel more comfortable about my ability to tackle minor problems than if I had to look around for an ATM, especially if I haven't been to that country before.