Limoncello is the second most popular liqueur in Italy and it has recently become popular in other parts of the world. Restaurants in the United States, Canada, the United Kingdom, Australia, and New Zealand are now increasingly offering limoncello on their beverage and dessert menus.
Limoncello is traditionally served chilled as an after-dinner digestivo. Along the Amalfi Coast, it is usually served in small ceramic glasses that are also chilled.
(Naturally, it goes great in cocktails as well -- but traditionally in small doses, due to its sweetness.)