In small saucepan, combine sugar and water; cook over medium heat, stirring constantly until sugar is dissolved. Remove from heat; cool to room temperature.
Add lemon juice; stir to blend. Store base mixture in tightly covered nonmetal container or jar in refrigerator.
For each serving, in tall glass, combine 1/2 cup chilled base mixture and 1/2 cup ginger ale. If desired, add ice.