Prep: 30 min . Look for seeded melon halves in the produce department to save a little time.
Cut first 4 ingredients into 1/4-inch pieces (about 2 cups each cubed strawberries, pineapple, and honeydew melon and 1 cup cubed cantaloupe). Toss with mint.
Arrange 1 lettuce wedge on each of 6 serving plates. Top evenly with fruit mixture. Sprinkle with salt and pepper to taste. Drizzle with Yogurt-Poppy Seed Dressing.