Sam's Club sells an AT&T card that is good for 3 cents/min in the US. To use it in the Caribbean, you have to call and get the access codes for that country (they give you instructions on how to do that). For W. Carib, they have access codes for Haiti and Mexico. In Haiti they charge you 24 minutes for every minute you talk ($.75/minute), Mexico is 10 min/min you talk ($.30). They have access codes for Cayman Islands, but when I asked for the rate it said that I couldn't use the card. No access codes for Jamaica. If you don't go this route, the best bet is usually to buy a phone card in the country you are in and use it to call the US. The best deal I've ever gotten like this was a card in Australia that allowed me to call home, offpeak, at 1.5 cents/min.