There are plenty of cool gift shops to buy all kinds of things to remember your holiday and share the Caribbean spirit with people back home.
One unique idea is Mamajuana a bottle of herbs and sticks that you fill with red wine, empty, then fill with rum and honey. It's for settling the stomach after dinner and makes a very cool addition to anyone's home bar. It is said that Mamajuana is also used for male vitality.
For healthier alternatives try a T-shirt or a photo CD of you taking kiteboarding lessons!
Cabarete is known world wide as a testing ground for kite manufacturers, so you can often find slightly used kites at discounted prices. And amazingly its cheaper to rent gear then to bring your own airlines have a $100 charge each way.