Lightly oil a 4-cup mold or small individual molds. In the top of a double boiler, sprinkle the gelatin over the orange juice, then set aside for 5 minutes. Add the lemon juice, ginger, sugar, and mint and stir to blend. Place the top saucepan over simmering water in the bottom of the double boiler and cook until the gelatin is dissolved. Remove from the heat, add the ginger ale, and stir. (Strain the mixture to eliminate the mint leaves, if desired.) Pour a thin coating of the mixture into the mold. Arrange the best-looking pieces of fruit decoratively in the thin coat of gelatin. (The fruit will appear on top when the dish is unmolded.) By tablespoonfuls, coat each piece of fruit with a portion of the gelatin mixture. Refrigerate for 15 minutes, or until the gelatin sets. Mix the remaining fruit into the remaining gelatin mixture and pour the combination into the mold. Refrigerate for 3 hours, or until the gelatin is firm. Unmold before serving.
*If using apples, peaches, or pears, cut them just before using so that they don’t turn brown.