Light the grill according to individual unit directions. Bring a large pot of lightly salted water to a boil.

Cut the tomatoes in half lengthwise, remove the stem ends and gently squeeze out the seeds. Lightly oil a shallow heavy metal baking pan, large enough to hold the tomato halves in one layer. Oil the pan lightly. Toss the tomatoes with 3 tablespoons olive oil, salt, pepper and sugar and place cut side up in the pan. Sprinkle with balsamic vinegar. Cover the pan with aluminum foil and place on the grill, over indirect heat. Wrap the garlic head with double strength aluminum foil and place on the grill rack, over indirect heat, too. Close the lid on the grill (make sure the vents are open) and smoke the tomatoes and garlic for about 20 - 25 minutes, until the tomatoes are soft and charred. Remove the tomatoes and set aside, covered to keep warm.

Boil the orzo to al dente. Remove, drain, and toss with 3-4 tablespoons of olive oil.

While the orzo is boiling, toss the shrimp with salt and pepper and grill, over the hottest part of the grill, for about 3-4 minutes per side. Remove. Remove garlic from grill, separate the cloves and squeeze out the pulp into the orzo.

Toss the orzo with the tomatoes, shrimp, olives, feta, remaining olive oil, lemon juice, and herbs. Adjust seasoning with additional salt and pepper. Garnish with fresh lemon wedges and fresh basil or oregano. Serve warm.