1 quart water
1 cup sugar
1 cup fresh lemon juice
Sparkling water (not tonic water, like Perrier)
Mix first three together. Fill a tall glass 2/3 to 3
3/4 with lemon mix then fill with sparkling water.
An intresting variation is to pure some fruit (raspberries, strawberry, etc) with a little superfine or powdered sugar and put that that in glass before adding the lemonade and water.
Yummy