I have made lemon, strawberry and water melon. It's super easy, and great for summer!
4 cups watermelon, seeds removed, cubed
Popsicle sticks (available at craft stores)
Place the watermelon in blender and puree. Pour into the paper cups, insert sticks and freeze until hardened. (You can use small Dixie cups or paper cups that are a little larger.)
2 cups fresh, or frozen strawberries
1 cup plain yogurt
1/2 cup granulated sugar
Puree the fruit in a blender. Pour into paper cups and freeze. Insert sticks when partially frozen and continue to freeze until they harden (overnight is good).