Melon Ball Salad with Lime Syrup

Combine the sugar, lime juice, and 1/4 cup water in a small saucepan. Stir over medium-high heat until the sugar is dissolved, about 5 minutes. Remove from the heat and add the lime zest. Cover the pan and set aside for 15 minutes. Pour into a small bowl, cover and refrigerate until completely cooled, at least 2 hours. (Can be prepared in 3 days).Cut each melon in half, remove the seeds, and scoop out the flesh with a 1-inch-thick sharp melon stick. Place all the melon balls in a large bowl, cover and refrigerate for 30 minutes before serving.Drizzle the melon balls with lime syrup. Cover and refrigerate for at least 30 minutes before serving. Divide into 8 cups and garnish with mint if desired.