A standard barge is 35 feet wide and 195 feet long. It is 12 feet deep and sinks nine feet below the surface when loaded, pushing through the water like a brick. A standard tow has 15 of these barges -- three wide and five long -- winched together with cables and stretching nearly 1,000 feet, enough for the farthest point to disappear into the horizon at dusk and still be out of sight, hours later, in the mist of a new day. Barges are a terrible way to ship iPods, automobiles, and anything that goes in your living room, closet, or refrigerator. They are built for shipping coal and grain and cement and benzene and asphalt, the heavy and still vital materials of our economy, products that are measured by the thousand ton, bushel, and barrel. There's no bar code. No real schedule. The barge could arrive today. Or maybe tomorrow.