Heat grill or broiler. In large bowl, combine zucchini, yellow pepper, onion, tomatoes, oil, salt, and pepper. Mix well to coat vegetables.
Thread pork on skewers, alternating with zucchini, pepper, onion, and tomatoes.
Coat grill or broiler racks with cooking spray. Place kabobs on grill over medium heat or on broiler rack 4 inches from heat source. Cook, turning occasionally, 12 to 15 minutes, or until vegetables are browned and pork is cooked through. Serve with Garlic Couscous.