Using a blender or food processor, blend oil with garlic, lemon juice and capers. Transfer to a non-metal container. Add fish and marinate 20 to 30 minutes, turning fish once in the process.
Meanwhile, prepare the grill or preheat the broiler. Remove fish from marinade and pat dry with paper towelling. Season with salt and pepper. (If using an indoor grill, spray fish lightly with olive oil or canola oil spray.)
Grill the fish about 4 to 5 minutes per side, depending on thickness of fish, or until fish is opaque in the center. (Fish usually takes about 10 minutes per inch of thickness to cook through.) Donít overcook or fish will be dry.
Serve with wedges of fresh lemon, either hot or at room temperature.