1. In large bowl, mix together flour, sugar, baking powder, baking soda and salt. Cut butter until mixture resembles fine crumbs. In small bowl, combine yogurt, eggs and orange rind. Add all at once to flour mixture. Stir just until combined. Gently fold in blueberries.
2. Divide batter evenly among 12 large greased muffin cups. Bake in 400 degree (F) oven for 20 to 25 minutes or until done. Makes 1 dozen muffins.