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 watersort of an environmentally savvy version of the tugboat.

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