For “lemonade,” empty lemon gelatin powder into a medium bowl. Add 1 cup boiling water and stir for 2 minutes until completely dissolved. Stir in 1 cup cold water. Pour mixture evenly into two drinking glasses. Add a straw to each glass and refrigerate until set, at least 2 hours.
For “fruit punch,” prepare strawberry gelatin as directed in Steps 1-2 above.
To serve lemonade or punch in a pitcher or small punch bowl, double the recipe, stirring in an extra ½ cup cold water. Pour into container and chill until set.
Before serving, garnish lemonade with lemon slices. Garnish punch with sliced oranges, limes, or strawberries.