Kid friendly Caribbean vacation destinations?

Hi, we are starting to look at a trip for 2011. 2 adults, a 7 year old and a 12 year old. We are looking for destinations easily accessible from Orlando, FL. We hope to be able to combine a trip to Disney with a island beach trip. Can you suggest any good, safe, kid friendly destinations? We have passports so leaving the US is no big deal. We don’t want a long flight from Orlando (maybe under 2 hours?). Thanks in advance!