Preheat the oven to 350°F. Bake the taco shells according to package directions.
While the shells are baking, heat the oil in a large nonstick skillet over medium-high heat. Add the shrimp, cumin, garlic powder, and chili powder and cook about 1 minute.
Add the beans, corn, pineapple, and salsa and heat through, about 2 minutes. Add the cheese and heat until melted.
Place about 1/3 cup of the shrimp filling into each of 12 taco shells using a slotted spoon to remove any excess liquid. Serve with optional toppings.
Source: Janice Newell Bissex, MS, RD & Liz Weiss, MS, RD Cofounders, Meal Makeover Moms.com