Can you carry enough string to make the cup and string work? Should be the cheapest option!
But seriously, do the have internet access? Maybe Skype or VOIP is cheaper? Jamaica seems like a place that might be tricky to find decent service.
"Political correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t*rd by the clean end"