Spoon equal portions of cream into 4 wide glasses or bowls.
Set 3 or 4 berries, stem end down, in each glass.
In a round-bottom zabaglione pan or in a double-boiler top, beat together port, sugar, and egg yolks.
Place round-bottom pan directly over medium gas heat or high electric heat; set the double boiler over simmering water.
Beat rapidly with a whisk or electric mixer until foam is just thick enough to briefly hold a slight peak when whisk is lifted, 3 to 5 minutes.
At once pour warm port foam over berries.
Garnish with lemon peel.