Hoverboards Catching Some Air: Photos

Marty McFly's hovering skateboard isn't here yet. But it's almost here, and that counts for something, right?

Now and again, the technology world will surprise you. Fifteen years into the new millennium -- amid radical advances in robotics, A.I. and biotech -- one of the year's hottest trends is … hoverboards? Yeah, kinda. The Hendo hoverboard, pictured here, is one of several projects riffing on Marty McFly's futuristic skateboard from "Back to the Future" movies.

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The

Hendo hoverboard

is entirely legit, as far as it goes: The device uses proprietary magnetic field technology to elevate a no-wheels skateboard about one inch above a copper-plated half-pipe surface.

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Big companies like Lexus are getting into the act. The luxury car maker's

Slide

project is a prototype hoverboard that uses special tracks with magnets embedded into the ground.

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A variation on the theme, this one-wheeled contraption from aptly-named

Hoverboard Technologies

uses an electric motor and internal gyroscope to give riders a range of 12 miles at up to 16 mph.

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The

NeoLev Hoverboard

takes the essential idea and miniatures it, with a playset for kids that features a quarter-inch levitation surface. The company's motto? "Wheels Not Included."

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Invariably described as a "hands-free Segway," the Dutch device known as the Oxboard is one of

several self-balancing scooters

jostling for position in the marketplace.

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French extreme sports outfitter

Zapata Racing

goes in another direction with their water-powered hoverboard, which uses a firehose-type propulsion system attached by hose to launch riders up to 16 feet above the waves.

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Earlier this month, NASA made

an announcement

that suggests hoverboard technology has truly arrived. The space agency is partnering with Arx Pax, maker of the Hendo hoverboard, to develop new kinds of satellite technology. Specifically, NASA wants to use the company's Magnetic Field Architecture system to manipulate tiny satellites in orbit -- without actually touching the delicate spacecraft.

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When a startup outfit called HUVr Tech recently released their

eye-popping demo video

, it looked as if real hoverboard tech had finally arrived. The video shows riders floating on hoverboards several feet above L.A. streets, with testimonials from skateboard ambassador Tony Hawk and "Back to the Future" star Christopher Lloyd. Alas, the video was eventually revealed as a Funny or Die prank.

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