In a medium bowl, combine the tomatoes, parsley, capers, oil, garlic, lemon zest and juice, 1/2 teaspoon salt and 1/4 teaspoon pepper.
Season the salmon on both sides with salt and pepper. Place each salmon fillet on a sheet of aluminum foil and top with a few tablespoons of the tomato mixture. Fold the foil sheets into packets. (If making this recipe in advance, store the packets on a baking sheet in the refrigerator until time to grill.)
Place the packets on the grill and cover. Cook 10 to 12 minutes for medium.