Preheat oven to 450. Sift together flour, sugar, baking soda, and salt into a mixing bowl.
Cut butter or margarine into small pieces and add to dry ingredients. Blend together until mixture is crumbly.
Make a well in the center of the mixture and gradually add the buttermilk, stirring gently with a fork. Fold in fruit and nuts. Mix just until soft dough is formed. (We use a food processor and pulse once for the dry ingredients and blend until just after all the buttermilk is added).
Turn onto a lightly floured surface pat into a circle ½ inch thick at the edge, with the center slightly thicker. Cut into 8 equal pieces. Place each of the 8 pieces on an ungreased baking sheet.
Bake for 12 to 15 minutes, until golden brown. Best served warm.