1. Thread the shrimp, red pepper and half the onion onto four 12-inch skewers, running the skewer through each shrimp twice. Thread the scallops, green pepper and remaining onion onto 4 more skewers. Place on a large shallow platter. Combine the lime peel, lime juice, oil, honey, garlic, pepper and salt. Pour over the skewers and marinate, turning occasionally for 15 to 20 minutes.
2. To make the salsa, toss the avocado with the lime juice and gently stir into the prepared salsa. Let stand 20 minutes or refrigerate up to 24 hours.
3. Coat the grill rack with vegetable cooking spray. Place kebobs on grill rack 4 to 6 inches over medium-hot coals. Grill, turning once, just until the seafood is opaque, allowing about 3 to 4 minutes on each side. Wrap tortillas in aluminum foil and heat them on the grill.