SEA BREEZE --  4 ounces grapefruit juice;   2 ounces cranberry juice;   1 1/2 ounces vodka;   lime wedge, for garnish -- Fill an 8 ounce glass halfway with ice cubes. Add grapefruit juice, cranberry juice and vodka. Give it a stir, garnish with a lime, and serve.  Alternately, you can use a cocktail shaker- place ice and ingredients in the shaker. Shake, then strain into a glass and serve.