Place potatoes in a large kettle with enough water to cover. Add half tsp. of the salt. Partially cover and bring to a boil over high heat. Boil gently for 15 minutes, or until potatoes are tender but still firm. Meanwhile, place dried tomatoes in a small bowl. Cover with boiling water. Let stand 10 minutes. Drain potatoes well; return to pot. Sprinkle olive oil and half tsp. of the salt over potatoes, tossing lightly to coat. Cut dried tomatoes into thin slivers and add to potatoes. Stir in celery, celery leaves, green onions, ad dill. Spoon into large bowl; cover and refrigerate at this point if preparting ahead. Combine sour cream, yogurt, horseradish, pepper and remaining half tsp. salt in a small bowl. Pour over potato mixture and toss gently to coat. Cover and refrigerate up to 24 hours. Makes 8 servings. Approximate nutritional analysis: 182 calories per serving; 4 g protein; 32 g carbohydrate; 5 g fat (24% of calories); 3 g fiber; 5 mg cholesterol; 522 mg sodium; 37% of the Daily Value for vitamin C. From the American Health, June 1995, page 90. Submitted By ARLENES@HOLLY.COLOSTATE.EDU On