1. Combine sour cream, mayonnaise, sugar and 1 TBS. lemon juice. Refrigerate until salad is prepared.
2. Soak cherries or cranberries in 1/2 cup boiling water until softened, about 10 minutes. Drain well.
3. Add chopped apples to a large bowl. Add 1 TBS. lemon juice and toss apples to coat. Add celery, cherries or cranberries and nuts to the apples and mix. Add dressing, folding gently to coat all the salad ingredients.
4. Chill salad for a few hours before serving.
5. Serve on lettuce leaves.