In a cocktail shaker filled with ice, add the vodka, orange liqueur, orange juice and lime juice. Cover and shake vigorously. Put a teaspoon-sized scoop of orange sherbet into each chilled martini glass. Strain the vodka mixture into the martini glasses. Garnish each glass with 2 orange slices and serve.
1 cup vodka
1 -ounce orange liqueur (recommended; Grand Marnier)