Heat a gas grill to medium-high heat. While the grill is heating, place a pot of water on the stove top large enough to submerge the corn and bring to a boil.
Place corn into boiling water and turn off the heat. Let corn sit in the water for 5 minutes. Removed and pat dry. While it is soaking move on to grilling the peaches (step 3).
Slice peaches in half vertically, remove pit keeping fruit intact. Slice each peach in half once more vertically to yield 4 large, thick slices per peach. Lightly brush each side of the peach slices with olive oil and place on clean grill grate. Cook only 2 minutes per side. Grill marks should be noted but the peaches should not fully cook; they should remain firm. Remove and set aside to rest while grilling the corn.
Brush the parboiled corn with olive oil, salt and pepper, and grill for 4-5 minutes turning as soon as char marks appear. Remove and set aside to cool.
When corn is cool enough to handle, cut kernels from cob and add to a large mixing bowl. Tips for removing the corn intact: My preferred method is using a corn zipper which removes the corn effortlessly (link in ingredients) and is a very inexpensive and useful too. Alternatively place a small mixing bowl upside down in a larger mixing bowl. Place the large, flat end of the cob (stalk should be sliced flat close to the bottom of the cob) on the top of the smaller upside down bowl. Using a large sharp kitchen knife cut off the kernels that will fall into the larger bowl now ready for your use.
Cut peaches into small pieces and add to the mixing bowl, followed by the remaining ingredients. Gently stir ingredients to combine. Salt and pepper to taste. Devour!