In a 3 to 4 quart pan, bring about 2 quarts water to a boil. Immerse peaches, 2 or 3 at a time, just until skin pulls free easily (to test, make a nick in skin and pull), 15 to 60 seconds. Lift out with a slotted spoon. Let cool slightly, then pull off skin and slice peaches; discard skin and pits. Gently mix slices with lemon juice. If making ahead, cover and chill up to 2 hours. To serve, present peaches, strawberries, and blueberries, together or in separate bowls. Also offer shortcake wedges, whipped cream, and powdered sugar. Let guests assemble their own shortcakes, spooning fruits and cream between split wedges of shortcake. Sprinkle with powdered sugar to taste. Serves 8. Per wedge with 2 cups fruit and 1/4 cup whipped cream: 557 cal. (37 percent from fat); 9.5 g protein; 23 g fat (14 g sat.): 83 g carbo.; 528 mg sodium; 70 mg chol. Garden shortcake wedges: Combine 3 cups all-purpose flour, 2 tablespoons sugar, 41/2 teaspoons baking powder, and 1/2 teaspoon salt. With a pastry blender or knife, cut in 1/2 cup (1/4 lb.) butter or margarine until mixture resembles coarse crumbs. (If making ahead, cover and chill up to 1 day.) Add 1-1/4 cups milk: stir just until dough sticks together. Lightly oil and flour a 10-inch round on a 12x15-inch baking sheet. Spoon dough into center of floured area and press into a 9-inch round. Cut dough into 8 wedges, leaving wedges in place. Bake in a 450° oven until golden brown, about 15 minutes. Transfer to a rack; pull wedges apart, slice horizontally into halves, and serve warm or cool. DESS153