Change it Up:
Instead of melted chocolate chips, garnish with hot fudge.
Dress it Up:
Add some fresh berries to the mousse. Rough chop a handful of blackberries or red raspberries. Gently fold in to prevent mousse from deflating.
Make this Dense Chocolate Mousse as well, and layer in ramekins or wineglasses.
Dress it Down:
Don't like lemon? Just eliminate it completely.