Phred, his idea about Charles Schwab is excellent and I have recommended that too. You pay no fees with them and they will reimburse any charges by any ATM in any country plus you can open an account with no fees and no money.
I think the Charles Schwab card is great, and have used it in many places. I recently got mine replaced for the version with the chip.
The only part of the article where I disagree a little is: "In your trip’s final days, carefully budget how much cash you will need, and try to stick to it. If you underestimate, you will end up paying a fee for a small cash withdrawal just to pay for a cab to the airport; if you overestimate, you will be getting rid of those soon-to-be-useless coins buying overpriced gum at the airport."
If you have the CS card, there isn't a fee for a final withdrawal for cabfare, and also, if I have extra money left over, I keep it for the next trip. I have a few reais in my dresser from my last trip to Brazil, many years ago, and will take it with me when I return next month so that I arrive with some money. Of course, this won't work if you never go to the same place twice.
However, I also took the pile of extra coins that had accumulated over the years and made collections for the kids in my family, which were well-received.
You can also donate unwanted foreign currency to charity where it will be very gratefully received!
Some British Airways flights provide special charity envelopes to put the currency and they have raised millions in this way.
The missus and me have had the Schwab card for about a decade. I have used it for two prior trips to Europe. Their customer service is the standard. This card is the best!
As noted, on some flights the FAs collect stray bills and coins and donate to charity. Some airports also have big piggy banks you can feed.
My experience at a money changer when back home is, they will take your bills but not your coins. Which is crazy since when I went to that place before my trip, they gave me my Swiss francs and Euros in bills and .... well you can guess.