I was able to use the Tune In Radio app on my phone last time I was in Negril, anywhere I had wifi access. I would assume that any internet radio app (such as Pandora, Slacker, I Heart Radio, etc) would work over wifi.

Next time I visit, I hope to be able to use it without needing Wifi, since my cell phone provider now includes free unlimited data (and texting) while in JA.