In a small bowl combine oil, garlic and red pepper. Brush cut surfaces of potatoes with oil mixture.
On a charcoal grill, grill potatoes cut side down over open grill for 20 to 25 minutes, or until tender; turning once half way through. For gas grill cook over medium heat cut side down on rack and cover closed.
Carefully scoop out the insides of each potato half, leaving 1/2 to 1/4 inch shell. Brush remainder of oil on potato shells, sprinkle with cheese and return potatoes to grill cut side up for 5 to 7 minutes more or until cheese is melted. Serve with avocado dip, salsa and sour cream.