Peel shrimp leaving tails intact. Devein shrimp; rinse and pat dry. Set aside.
Cook zucchini in a small amount of lightly salted boiling water for 2 minutes; drain. On eight 12-inch skewers, alternately thread shrimp, zucchini, and red sweet pepper.
In a small saucepan cook garlic in margarine or butter. Stir in lemon peel, lemon juice, ground red pepper, and salt. Set aside.
Grill kabobs directly over hot coals for 5 minutes. Brush kabobs with lemon mixture. Turn kabobs and brush again. Grill for 3 to 7 minutes more or until shrimp turn opaque. Serve with lemon wedges, if desired. Makes 4 servings.