Using a very sharp serrated knife, slice bagel into very thin rounds. Arrange in single layer on baking sheet; brush with margarine. Sprinkle with oregano. Bake in 350F oven for 12 minutes. Let cool and store in airtight container for up to 1 week. Per 1 piece serving: 14 cal; .5g fat, 0 cholesterol, 15 mg salt.