Heat a large skillet over medium-high heat. Coat pan with cooking spray. Add shrimp to pan; cook 4 minutes or until done, stirring occasionally. Stir in barbecue sauce; cook 30 seconds. Sprinkle shrimp mixture evenly with salt.
Brush bread slices evenly with 1 1/2 tablespoons oil. Broil 1 minute on each side or until toasted. Rub toast slices with cut sides of garlic.
Toss arugula with remaining 1 1/2 teaspoons oil. Top toast slices evenly with arugula and shrimp. Sprinkle evenly with pepper.