Ingredients:
 
3/4 cup lemon juice
1 (46-oz.) can (about 6 cups) pineapple juice, chilled
1 pint (2 cups) lime sherbet, softened
2 (20-oz.) bottles (about 4 cups) lemon-lime flavored carbonated beverage, chilled
 
Directions:

Combine the lemon juice, pineapple juice, and sherbet in a large punch bowl. Gently stir everything until the sherbet is completely dissolved.
 
Slowly pour the sodas into the pineapple juice mixture just before serving.