Place fish and bell pepper in a shallow dish. Drizzle pesto and vinegar over fish mixture; toss to coat. Let fish mixture stand 5 minutes.
Thread fish and pepper alternately onto each of 4 (12-inch) skewers; sprinkle evenly with salt. Place skewers on a jelly-roll pan coated with cooking spray. Broil for 8 minutes or until desired degree of doneness, turning once.
If you can't find fresh halibut, substitute another mild, firm white fish.