Cut potatoes lengthwise into thin 1/4-inch strips. Pat dry with paper towels. In a bowl, combine the egg whites, parmesean cheese and garlic powder. Add the potatoes; toss to coat. Place in a single layer on a 15x10-inch cookie sheet coated with non-stick cooking spray. Bake, uncovered, at 375° for 35-40 minutes or until potatoes are golden brown and tender, turning several times.