ANDOVER - Inventor Kurt Eldracher jumped up and spun around in the air, did a bunch of sit-ups and lifted his arms up and down as if trying to fly. Then he ran and hopped from one end of Yang's Fitness Center to the other.

Stopping, he pointed to the back of his neck, where an iPod Nano rested securely in his new invention, appropriately called "nekFit."

"Forty million people will exercise with an iPod this year," he said, panting. "The iPod is the number-one fitness product in the world. And the only thing available in stores now to hold it while you're exercising is an armband."

Until now.

After 11/2 years of research and design testing, and the expenditure of $150,000 of his own money, Eldracher last month unveiled the nekFit, an accessory born of necessity.

The Andover entrepreneur and exercise nut had been training for the Hyannis marathon when in his workshop he cobbled together a device that could hold his iPod without the annoying earbud cables flailing around him as he ran.

"I used a piece of copper wire, a couple of rubber fishing worms and one of my daughter's hairbands, strapped the iPod to it and put it on the back of my neck," said Eldracher, an energetic 48-year-old. "I went out and ran five miles, and later, I forgot I had it on."

Fast-forward to Oct. 20, 2007, after 14 different iterations of the device, and the product is finally making its public debut at a booth during the Head of the Charles Regatta in Boston.

"I was sitting in a tent at the regatta and 200 orders came in," he said, adding that he also was approached by one of the top crew outfitters in the world, and representatives from a major catalog company and a superstore interested in selling it.

He said the prevailing theme of the day - which his daughter translated for him - was: "This is sick," which in modern-day parlance means "very cool."

Eldracher, a part-time inventor and entrepreneur, works full-time managing sales and development for start-up companies. He also has started two of his own companies - with mixed results.

He hopes the third time is the charm.

"I have been given a valuation of $2 million in annual sales," he said of nekFit. "I will easily get back my investment."

In addition to selling nekFit at places like Yang's and Athlete's Corner, which has locations in Andover and Swampscott, Eldracher recently bought a retail kiosk at the Burlington Mall. It sits close to the Apple store and he hopes to cash in on holiday buying. Plus, the product, which sells for about $34, is available on the Web.

He said a lot of thought and engineering went into the designing nekFit. The two biggest advantages of using it are the elimination of dangling wires and allowing users to remain hands free. People have told him beyond using it for indoor and outdoor exercising, nekFit also would be great for gardeners and weekend warriors working on ladders painting their homes, for instance.

The adaptability of the product, he said, is both in the concept and the design. He said he worked closely with renowned industrial design engineer Gerd Schmieta, a former employee of international design giant Ideo.

Together, working on the backs of paper napkins at Boston restaurants, they advanced the product from hair bands and copper wire to a more sophisticated look and feel.

Now, the device comes in clear plastic, white and black, and is made of steel and Lexan. A slender piece of steel holds the two pieces of contoured Lexan, shaped like the stems of a pair of sleek eyeglasses, together. In the center is a hard piece of plastic against which the iPod is held using a flexible silicon strip.

Once the iPod is strapped in, earbud cables are secured using a cleat system similar to something you might see on a boat - albeit a very small one. NekFit comes in three different sizes, based upond the girth of the neck, and the flexible silicon strap can hold all iPod Nano and Shuffle models.

Eldracher said nekFit is an all-New England product, having been designed and manufactured here. The silicon strip, for example, is made by UPCOA, a liquid injection molding company in Peabody's Centennial Industrial Park. The Lexan stems are molded by a Western Massachusetts company.

Some users have given it the thumbs-up, too.

Jamey Lachiana, who works as a trainer at Yang's, said in the past he used an arm strap to hold his iPod while working out. What he likes about nekFit, he said, is that when he's lifting weights he doesn't have to keep adjusting the strap, which typically slides up and down as his arms expand and contract.

Also, he said, when he clips his iPod to his waist, the earbuds pop out when he lifts his arms over his head.

"You lift up your arms and you get the rip-out," he said.

Eldracher said that while he's excited about his new venture, he's got some perspective.

"Is this the end of the earth?" he asked. "No. It's just an accessory."

But, he said, if it gets more people motivated to exercise - because they can listen to their favorite music while jogging or doing jumping jacks - then nekFit will be a success.