Jeff Bell at Manhattan's PDT (one of the best bars in the world) freezes coconut water and a mix of fruit juices, then blends them with rum to make a terrific, superfresh version of the classic cocktail. Slideshow: More Frozen Drinks
Mix the pineapple juice, lime juice and coconut water; freeze in an ice cube tray until solid. Transfer the ice to a blender. Add the rum, coconut puree and cane syrup; blend until smooth. Pour into 4 chilled double rocks glasses; garnish with the pineapple.