In a small pan, bring brown sugar, 1/2 cup water and chopped fresh ginger to a boil, stirring just until sugar dissolves. Reduce to a simmer; cook 5 minutes. Remove from heat, cover and let steep 10 minutes. Strain; discard ginger. (You should have about 1/2 cup.) Combine ginger syrup, pineapple juice and cranberry juice cocktail in a 2-quart container. Chill for at least 3 hours or overnight. Just before serving, combine juice mixture with chilled ginger ale and chilled club soda in a large bowl.