Yes you will need to get an international converter. Only US and Canadian devices will work on the 110v. Converters are typically sold by country, so look for one for Jamaica (or the Caribbean). I purchased one for a trip to Spain that had multiple locations for around $30 (US).
A lot of the "wall wart" transformers will be fine with anything between 100V to 240V, you'll just need the right pins to put in the wall. Look at your ipod charger or laptop power supply or cell phone charger. There is a label that will tell you what acceptable input voltage is, and it probably says 100V-240V... I've tested this in the real world many times.. You will be okay IF you stay in the limits of 100V -240V which catches almost every thing.
A lot of cell phones come with several sets of pins that you can swap, or you can get an adapter.
Now... repeat after me.
THE ADAPTER DOES NOT CHANGE VOLTAGE It just changes pins. If you use an "adapter" on something like say, a curling iron or a TV, you may just let all the magic smoke out of whatever you plugged in. Once the magic smoke is out, its a done deal.
Converters do change the voltage Since it has a transformer inside it will be heavier and larger than the adapter and you CAN plug your curling iron into it. There jury is still out about the magic smoke though... If you cheaped out on your converter and it can't handle the wattage of your 1500 watt curling iron, you may be sorry.