Fujitsu is taking the mobile PC one step further.

The PC manufacturer is in France this week showing off a prototype of a laptop that folds down into the size and shape of a CD case. Whether or not the company moves forward to develop and market the purse-sized laptop largely will depend on the reaction it receives at the International Industrial Design Fair, according to Sean Nemoto, a spokesman for Fujitsu.

"Pretty much, the fate of the prototype rests with the response we get," he said. "Normally, the lightweight mobile PC is for the businessman because he always carries a mobile PC and handset. This should reach beyond the businessman. This is quite unique."

The prototype, called the Ultra Mobile PC, is the size of a CD case when it's folded up. Then the user flips open an 8-inch display screen, just like he or she would on a normal laptop. But at this stage, the keyboard still is hidden. The user then flips open the keyboard, lifting it from left to right to open it up. When it's open, the keyboard will be about 16 inches wide, said Nemoto, who added that designers have been working on this for about a year.

He also said the laptop would be "very much lighter" than a normal notebook, but they're not yet sure what the exact weight would be. He also said they haven't made any decisions about what processor the machines would run or about any of the operating specifications.

"It's quite hard to say because it's a prototype and we need to consider [a lot of things] before we decide to commercialize," said Nemoto, speaking to InformationWeek from the design fair in France. "We haven't gotten to the production phase. There will be many discussions about this."

The design fair starts on Wednesday and runs through to early next week.