On the last morning of our Riviera maya vacation in Mexico, we had to be ready in front of the hotel at 6:45 AM to take a bus up to the Cancun airport an hour away and there was little to no breakfast available to be scarfed at that hour. So, upon arriving at the airport, I ended up getting a very unbreakfasty 9:30 AM meal of pizza and Coke. Price: $10.

Technically it was a bit less than $10, but they took my $20 bill, gave me a $10 back, plus about 8 pesos. Eight pesos isn't going to get you much, especially once you're in the airport, so the change became Mexico souvenirs for my kids.

Your U.S. money still does pretty well in Mexico... but not en el aeropuerto.