For marinade, combine onion, Worcestershire sauce, lime peel, lime juice, rosemary, and oil in a medium mixing bowl. Place chicken, lamb, beef, and vegetables in a 1-gallon sealable plastic bag set in a shallow dish. Pour marinade over mixture. Seal bag; chill for 6 to 24 hours, turning bag occasionally. Drain, reserving marinade.
Thread different combinations of meat and large vegetable pieces on 8-inch skewers. Thread smaller vegetable pieces on skewers. Transfer reserved marinade to a saucepan. Bring to boiling. Reduce heat; simmer for 5 minutes. Set aside.
Place meat skewers on the rack of the grill directly over medium-high heat. Grill for 16 to 18 minutes or until juices run clear and no pink remains, turning several times. Grill all-vegetable skewers on grill rack beside meat skewers for 6 to 8 minutes or until edges are slightly charred, turning several times. Pass heated marinade. Makes 6 servings.