'It' is back, but the invention also known as Ginger still remains shrouded in mystery.

The elusive gizmo referred to as 'It' or 'Ginger' was first rumoured early this year as an invention that would revolutionise the world — in some way. And after a whirlwind of media speculation that turned up, well, more speculation, 'It' is back.

US television show Good Morning America says it will unveil the invention during on Monday next week's show, a spokeswoman confirmed.

Ginger is the work of the lauded New Hampshire inventor Dean Kamen, who made his millions inventing a plastic kidney-dialysis machine and later a versatile wheelchair that climbs stairs and stands on two wheels.

But despite the clamour of interest from media outlets everywhere, which have written and speculated about Ginger since it was first mentioned, there are few clues as to what Kamen's hyped invention will be.

Internet discussion boards dedicated to Ginger offer guesses ranging from a hovering transport device to the more popular conclusion — a personal scooter powered by a clean-running engine called the Sterling.

But apart from speculation, few know for certain what Ginger is, and promotions about its debut next week offer little else. Good Morning America host Diane Sawyer mentioned Monday's unveiling of Ginger on the morning news show last week, noting that "we don't know if you eat it, or you ride it, or you co-anchor with it", according to reports, citing show transcripts. What they probably do know is that the covert invention could attract big ratings.

Kamen's invention has won over some of Silicon Valley's bigwigs who have seen Ginger and reportedly thrown money behind it, according to initial reports in January on the news website Inside.com.

Investing icon John Doerr has called Kamen a blend of Thomas Edison and Henry Ford. Apple's head honcho Steve Jobs was quoted as saying that people will erect entire cities around It.

News of Ginger was first uncovered when it was revealed that Harvard Business School Press had offered Kamen $250,000, with the help of a writer, to chronicle the making of Ginger in a book.