Combine the whiskey, lemon juice, lime juice and syrup. Fill a cocktail shaker halfway with ice and fill two-thirds full with the cocktail mixture. Shake for 30 seconds and pour into glasses. Add a maraschino cherry and serve ice cold.
Sugar syrup: Put 1 cup sugar and 1 cup water in a small saucepan and cook over medium heat until the sugar dissolves. Chill thoroughly before using.
Photograph by Quentin Bacon
Recipe courtesy Barefoot Contessa at Home (c) 2006 by Ina Garten. By arrangement with Clarkson Potter/Random House, Inc. for Food Network Magazine