1. Preheat oven to 350. 2. Place crackers in a food processor, and process until crumbly. Add sugar, margarine, and egg white; pulse 5 times or just until moist. Press crumb mixture into a 9-inch pie plate coated with cooking spray. Bake at 350 for 8 minutes, and cool on a wire rack 15 minutes. Freeze piecrust 30 minutes. 3. Place an extra-large bowl in freezer. Remove yogurt from freezer; let stand at room temperature while crust is cooling. 4. Spoon yogurt into chilled extra-large bowl. Fold lemonade concentrate into yogurt; freeze 30 minutes or just until set but not solid. Spoon yogurt mixture into prepared crust; freeze until set. Cover with plastic wrap; freeze 6 hours or until firm. 5. Place pie in refrigerator 30 minutes before serving to soften. Serve pie with Blueberry Sauce. Yield: 8 servings (serving size: I wedge and 3 tablespoons sauce). CALORIES 260 (18% from fat); FAT 5.2g (sat 2.1g, mono 1.2g, poly 1.7g); PROTEIN 4.7g; CARB 50.3g; FIBER 1.6g; CHOL 9mg; IRON 0.8mg; SODIUM 153mg; CALC 104mg (from Magazine) Recipe by: Cooking Light Magazine Posted to Digest eat-lf.v097.n202 by Irene DiGiuseppe on Aug 10, 1997