Pineapple-Mint Lemonade: Stir 3 cups pineapple juice and 1/4 cup mint leaves into the lemonade before adding the ice cubes, and serve.
Watermelon Lemonade: Purée 2 cups seedless watermelon chunks; stir into the lemonade before adding the ice cubes, and serve.
Berry Berry Lemonade: Thaw and purée a 10-ounce package of frozen mixed berries with 1/4 cup honey; stir into the lemonade before adding the ice cubes, and serve.
NOTE: Serve in tall glasses garnished with lemon slices. If making this in advance, don't add the ice until ready to serve.