Heat oven to 425 degrees F. Unroll the pizza dough onto a lightly floured surface. Roll into a 13-1/2x9-inch rectangle. Cut dough into six 4-1/2-inch squares. Place squares about 1 inch apart on a lightly greased cookie sheet. If desired, fold over about 1/2 inch of dough on each edge; press with a fork. Bake for 4 to 5 minutes or until lightly browned.
Place three or four tomato slices on each square. Top each with four to six pieces of shrimp. Sprinkle with oregano and crushed red pepper. Sprinkle with cheese. Bake 5 to 6 minutes more or until cheese melts. Makes 6 servings.