1. Thread shrimp equally on 10 to 12 skewers (if using wooden ones, soak in water 30 minutes first). Reserve 1/2 cup salsa for serving; coat shrimp with remaining 1/2 cup.
2. Set shrimp on a barbecue grill over hot coals or high heat on a gas grill (you can hold your hand at grill level only 2 to 3 seconds); close lid on gas grill. Cook, turning once, just until shrimp are barely opaque but still moist-looking in center of thickest part (cut to test), 4 to 6 minutes total. Serve with reserved 1/2 cup salsa and lime wedges.