Photo: Cruise ship of the sky?

Dubbed the cruise ship in the sky, the 174mph, 400-ton craft is more than an acre in size. Created by California-based Worldwide Aeros, the Aeroscraft is in a category of its own, said inventor Igor Pasternak, who expects the prototype to be completed by 2010. "You can land it on water or snow," he said. "It's a new vision of what can be done in the air."

When it's completed, the cross between an airship and a plane will ferry passengers across continents and oceans. The company hopes to create both commercial and military versions.