You cannot make whipped cream with anything other than cream. Don't let anyone tell you anything different. We're really sure about that.
for frostings, the sky's the limit! One of the classics is Royal Icing, basically a combination of egg whites and confectioner's sugar that is not much when it comes to flavor, but is popular for decorating and for gluing gingerbread houses together, because it sets up like concrete.
Another classic frosting is the rich Italian Meringue, in which a boiling sugar syrup is beaten into the whipped egg whites, creating a stable, spreadable frosting.
Finally, perhaps the best-known but somewhat out-of-favor egg-white frosting is the:
2 egg whites 1-1/2 cups sugar 5 Tbsp water 1/4 teaspoon cream of tartar 1-1/2 tsp light corn syrup 1 tsp vanilla extract
Off the heat, combine the egg whites, sugar, water, cream of tartar, and corn syrup in the top of a double boiler and mix until thoroughly blended. Place the top of the double boiler over rapidly boiling water and beat with a hand mixer or energetically with a wire whisk for 7 minutes. Add the vanilla and continue beating until the icing reaches a good consistency for spreading.
Note: Because of concerns over salmonella, some people use pasteurized meringue powder instead of fresh egg whites in any recipe where the eggs are uncooked or only partially cooked.