However, all the people you may want to communicate with (assuming it will be other APATers?), will be an international call for you (costly?) and they will have to pay to receive said call.
Cell/Mobile service in Vegas is generally flaky, I have found, and a hybrid solution using texts/emails is my preferred method.
For calls, it depends on the individuals roaming agreement...some will charge you an international call and some local.
In the past, I have always found it best to send texts which are generally cheaper than calls. I have had occasions though where texts have just vanished into the ether so this time round, I"m going to ask for emails which will get delivered direct to my phone.
I"m sure we"ll whip up a phone/email list before we go...just another thing to add to the list.
EDIT: Forgot to add that Twitter and Facebook updates work well too!