Pour honeydew and cantaloupe soups into separate small pitchers.
With a pitcher in each hand, simultaneously and gently pour soups into a soup bowl (use 1 1/2 to 2-cup size; wide bowls create the most dramatic effect).
Allow 1 to 1 1/3 cups soup total for each portion.
Repeat to fill remaining bowls.
Top each serving with a dollop of sour cream and a mint sprig.