Heat oven to 350º F. Lightly coat a 5-by-9-inch loaf pan with vegetable cooking spray. Combine the flour, sugar, baking powder, and salt in a large bowl. Using your fingertips or a pastry blender, work the butter into the dry ingredients until it looks like coarse crumbs. Mix in blueberries and lemon rind. Stir in the milk and eggs until well blended. Pour into pan. Bake 55 minutes or until a toothpick inserted in the center of the loaf comes out clean. Turn onto a wire rack.
VARIATION: For Orange-Raspberry Bread, use the grated rind from 1 orange in place of the lemon rind and substitute 1 cup raspberries for the blueberries.