Meanwhile, pull off and discard tough crescent-shaped muscle, if any, from each scallop; rinse to remove sand from crevices. Pat scallops dry.
From Lemon, grate 1 teaspoon peel and squeeze 2 tablespoons juice. In a bowl, toss scallops with garlic, 1/2 teaspoon peel, 1/4 teaspoon salt, and 1/4 a teaspoon coarse black pepper.
With vegetable peeler, slice each squash length wise into this, long ribbons until you reach the core with seeds; discard core. Set aside ribbons.
In non-stick 12-inch skillet, heat margarine over medium-high heat until melted. Add scallops and cook 5 to 6 minutes, until browned and just opaque throughout, turning over once; transfer scallops to plate. Add squash to same skillet. Reduce heat to medium; cover and cook 2 minutes, stirring once. Uncover and cook 1 minute or until tender-crisp. Remove squash from heat; stir in lemon juice and remaining peel.
Spoon vegetable mixture onto 4 plates; top with scallops and sprinkle with chives. Serve with couscous.