With oil prices recently breaking the psychologically important barrier of $100 per barrel, commuters aren't the only ones feeling the heat. Cargo vessels are responsible for moving 98% of all intercontinental goods, and a transatlantic crossing on fully-loaded 200-meter ship is not light on the diesel consumption. So far, at least two companies promise to deliver a technology not seen on massive ocean-going ships in quite some time: the sail.

In PopSci's May 2006 feature "Welcome to the New Age of Sail," we present three novel designs for systems capable of reducing the amount of fuel used by big ships by up to 35 percent. One of these is the SkySail, a huge kite that can be retrofitted to existing ships to help pull them across bodies of water–sort of an environmentally savvy version of the tugboat.

Click here to see a video of the SkySail system in action (Windows Media Player required).