Drain blueberries and pineapple; reserving juice. Dissolve gelatin in boiling water. Add 1 cup pineapple and blueberry juice. Stir in drained fruit and pour into 2 quart dish (9 x 13 works well). Refrigerate to congeal.
Soften cream cheese and fold in sugar, sour cream, vanilla, and pecans. Spread over congealed salad.
Prep time does not include time for salad to congeal.