Scott.
When my wife and I were there last week, we bought a 500 minute card from ATT at Walmart (before we left). On the island, use the hotel to connect with the AT&T operator. When they ask for the number to call, enter the 1-800 number on the card and then just follow the directions. It takes about 400 of your minutes to connect, but if you don't hang up when your party does, you can make a second or third call at no additional conect fees. Then before you do hang up, use a credit card and put 400 minutes back on the card for about $20.00.
It might sound expensive, but to use the phones on the island that are labeled "Call US", I checked into those. It was a $35.75 connect fee then $1.95 per minute rounded up.
The internet is by far the cheapest way to go. It was $4.00 (USD) for 15 minutes. Just remember, unless you are really fast at typing, 15 minutes is not very long. I figured out real fast not to waste time with spell check. Let the loved ones back home just figure out what you are saying.
enjoy the trip.