1) Grind the cranberries and combine them with the sugar and marshmallows.
2) Cover the mixture and chill it overnighr.
3) The next day, add the grapes, apples, walnuts and salt.
4) Whip the cream and fold it into the fruits.
5) Chill the preparation.
6) Transfer the chilled Cranberry Waldorf to a large bowl or put scoops of it into individual lettuce cups and serve. Best when served chilled as a dessert.