Lemon Drop Martini #2

1 - 1 1/2 oz Absolut Citron vodka
1 - 1 1/2 oz limoncello lemon liqueur
2 oz sweet and sour mix
1 - 1 1/2 oz fresh lemon juice
1 tsp sugar

Combine ingredients in a cocktail shaker half-filled with ice cubes; shake well. Swirl half a lemon around the rim of a margarita glass and dip in sugar. Pour the contents of the cocktail shaker into the glass, and serve.