Heat oven to 325°F. In medium bowl, mix salsa ingredients (salsa will be juicy). Set aside.
Heat taco shells in oven as directed on box.
Meanwhile, microwave chicken as directed on package. In large bowl, mix mayonnaise, sour cream, 1/4 cup pineapple topping, the celery, onions and 1/4 cup of the cheese. Cut chicken into small bite-size pieces; add to mixture in bowl. Toss gently, coating chicken completely.
To assemble tacos, divide lettuce among taco shells. Top lettuce in each shell with about 1 teaspoon salsa and 1/4 cup chicken filling. Top with remaining salsa and 1/2 cup blue cheese. Serve immediately.