Whisk together the package of jello and hot water in a mixing bowl or measuring cup with a spout.
Stir in the pineapple juice once the mixture has dissolved. Then pour in the rum and triple sec.
Pour evenly into the plastic cups, leaving a little room at the top for the garnishes.
Chill the jello shots in the refrigerator for 4 hours or until they are set. Garnish each shot cup with whipped cream, cherries, toasted coconut, or pineapple wedges and serve!