Consider it the year of the mojito. Until recently this refreshing, minty cuban cocktail barely registered on mainstream bar radar. For a long time the mojito -- pronounced mo-HEE-toe -- was the secret of Americans who'd tried the drink in Cuba, or foodies who ate at the few local Latin-inflected restaurants that served it at the bar.

Now they're everywhere. The mojito, with loose mint leaves floating around the glass, looks like a combination of a mint julep and a gin and tonic. You can order one at upscale international bars (Bomboa), at hip neighborhood lounges (the B-Side), and even at chain restaurants (Naked Fish).

No one really knows just why this combination of mint, rum, sugar, and lime has suddenly caught on. Maybe because its lean, crisp flavors appeal to beer drinkers and foofy-drink hounds alike. Maybe it's because of the Cuban renaissance in American culture. Bomboa bartender Liz Moses says, "I think it's just the way they look. People sit down and go, `What the hell is that?' "

One practical reason offered by Joe Carbonara of South End Galleria, where mojitos have been on the menu since the doors opened in April: they're a great summer alternative to body-warming martinis and the warm-weather staple, margaritas.

The man who may have brought the mojito to Boston is Paul O'Connell, owner of Chez Henri, in Cambridge, which has featured the drink for five years. The authentic mojito, according to O'Connell, starts with the proper ingredients: fresh lime juice, fresh mint, and so on. You also need a muddle -- a long wooden pestle -- to mash it all together in a tall glass. O'Connell says it's important to be aggressive with the muddle: the more mint oil released, the better the mojito tastes.

But beware of mojito impostors. Some bars and restaurants are substituting ginger ale for the soda water, or even a mint-sugar syrup to save the time it takes to mash the ingredients together. This makes die-hards like O'Connell cringe.

"That's just not right," he says.