A fellow FlyerTalk member is visiting the Cayman Islands. For the first time on this trip, he was able to charge in KYD on a US card, not have the merchant convert 0.80 KYD = 1 USD (as opposed to the official exchange rate of 1 KYD = 1.20 USD). The catch is that this only works with Amex. A Visa or Mastercard will still go through a USD terminal. According to a small merchant there, Amex sent some people to the Cayman Islands a few months ago to meet with local businesses to try to to encourage increased acceptance of Amex.