Grapefruit "Martini"

4 very large white grapefruit 3/4 cup best-quality orange marmalade1 piece, 4 inches long, fresh ginger Place martini glasses in the freezer for 30 minutes for a frosty look.Using a small sharp knife, cut all the rind from 1 grapefruit in long thin strips, making sure to also remove the white pith from the rind and from the flesh. Set strips of rind aside. Cut the rind and pith from all the grapefruits. Holding grapefruit over a bowl to catch juices, cut between membranes to release segments and place segments in a large bowl.Collect 1 cup of the juices and place in a small saucepan with marmalade. Bring to a boil, stirring until smooth, and pour over the grapefruit segments.Peel ginger with a sharp knife. Grate on the large holes of a box grater and place the shaved ginger in 2 layers of paper towels. Squeeze the ginger over a small bowl to extract 1 1/2 to 2 tablespoons juice. Add to bowl with grapefruit. Cover and chill several hours, until very cold.Fill chilled glasses with grapefruit and top with juices to cover. Garnish with a long, thin strip of grapefruit rind. Serve immediately.Serves four.Nutrition values per serving: 235 calories, 1 g fat (0 saturated), 61 g carbohydrates, 3 g fiber, 2 g protein, 0 cholesterol, 34 mg sodium."Desserts 1-2-3: Deliciously Simple Three-Ingredient Recipes" by Rozanne Gold