Soak apricots in water for 5 minutes. In a large bowl, cream sugar and butter until fluffy. Add sour cream; mix well. Combine dry ingredients; stir into creamed mixture just until moistened. Drain apricots, discarding liquid. Fold apricots, orange zest and nuts into batter. Fill greased or paper-lined muffin cups three-fourths full. Bake at 400° for 18-20 minutes or until muffins test done. Cool 10 minutes before removing to a wire rack.