It could be the perfect answer for people who would like a computer, but do not have the desk space.

Watch Sue Nelson report on the miniature computer

IBM has developed a portable personal computer that is as powerful as a laptop yet light enough to be worn on a belt.

The Wearable PC is far removed from conventional machines.

It does not need a keyboard or a TV monitor and it uses the smallest hard disc drive in the world.

As for size, it is not much larger than an English pound coin

The world's first modern computer may have been called Baby but it was the size of a large nursery. More than 50 years later computers are more powerful and much smaller.

Baby: the size of a large nursery

Weighing only 10 ounces, the Wearable PC is connected to a headset with a small perspex block at the end of a spectacle arm.

This is the miniature liquid crystal display computer screen. It is positioned in front of an eye but a combination of optics and mirrors produces a virtual image of a 17 inch screen about 25 inches away.

A hand-held switch then doubles as a mouse to select screen icons and a microphone for voice-activated software.

An innovative new microdrive provides the processing power and the PC is capable of storing 340 megabytes in a device the size of a 50 pence piece - that is more information than can be stored on 236 floppy discs.

Sue Nelson tries out the Wearable PC

Bob Tomalski from Computer Video Magazine says: "With miniaturisation of the computer comes a miniaturisation of the product.

"So in future you'll have products which will be able to do very much more because at their heart there is a microcomputer, not just a microchip, but a complete computer, complete with memory, storage and control."

There are six working prototypes - all designed and built by IBM in Japan.

The wearable PC could be used as a hands-free manual by technicians, and will hit the high street in around two years, when people can start reading their e-mails on the move.