In a large bowl mix together cumin, oregano, salt, pepper, olive oil, lime zest, and lime juice. Add shrimp and toss to coat. Let stand at room temperature for 10 minutes to marinate. Thread the shrimp onto skewers and reserve the marinade.
Lightly grease and heat an outdoor grill to medium heat. Place skewered shrimp onto the grill and cook for 3-7 minutes or until shrimp turn pink turning once and brushing occasionally with the reserved marinade.