In a large bowl or zip lock bag combine shrimp, salt, cumin, chili powder, oregano, garlic powder, and lime juice. Mix well and toss shrimp to coat. Place into the refrigerator and let marinate for 10 minutes.
In a large skillet heat vegetable oil. Add green onions and peppers. Cook while stirring for 2 minutes or until vegetables are slightly softened.
Add shrimp with the marinade and cook while stirring for 3 minutes or until the shrimp are pink.
Spoon shrimp and vegetables into warmed tortillas.