Fill two large wine glasses with layers of peaches and watermelon. Pour in white zinfandel until the glass is full. Sometimes if my peaches aren't very sweet I sprinkle about a 1/2 teaspoon of sugar on top of the fruit before pouring in the wine. I usually let them set in the fridge for at least a half hour, but you could probably serve them right away if all your fruit and wine is already cold.