Quite a Pear

In a small saucepan, combine 2 of the rosemary sprigs with the water and sugar and bring to a boil over moderate heat, stirring to dissolve the sugar. Let cool, then strain the syrup into a pitcher. Add the lemon juice, vodka and pear liqueur and stir well. Cover and refrigerate until chilled, about 2 hours. Pour one-third of the mixture into an ice-filled cocktail shaker. Shake well and strain into 2 martini glasses. Repeat 2 more times, using fresh ice each time. Garnish each drink with a sprig of rosemary and a lemon wheel.