I will eventually end up with so few US dollars when in San Francisco airport, that I won't have to declare them to customs when I arrive at Greece.
Should I convert them to Euros in SF, or in El. Venizelos airport at Athens? Or it's pretty much the same fees in both cases?
Also pleas explain, because I have no idea how all this works. I think you are suggesting go going to the bank in Greece and give them my US dollars?
How else do you think you can exchange dollars to euros? Of course you have to give them your dollars.