In a 2-quart saucepan, combine the barley, bulgur, oats and 3 1/2 cups water. Bring to a boil, and then reduce to a simmer and cook until the grains cook through, 10 to 12 minutes. Stir in the raisins and cinnamon, and continue to simmer until the raisins plump slightly, if desired. Divide among 4 bowls and top with the nuts. Serve the cereal with milk, if you like.