Breaking a cell phone into two isnt something that a consumer would look upon having to do. While it does happen from time to time, causes usually are something on the extreme such as when being caught cheating by the girl friend or wife. NTT DoCoMo is however intent on 'breaking' from this tradition by introducing a cell phone which can be divided into two and used seperately. Doing so will enable users to use the handset more easily.

The Seperate Keitai , as it has been named would allow you to seperate the display from the keypad. This would mean its much easier to indulge in different functions without the added cost of another device. For example you could make a call while simultaneously reading the email or referring to your schedule.

The seperate keitai was never joined to begin with. The design which is similar to any other clamshell is held together by magnets. The two parts communicate with each other using Bluetooth technology.

The two pieces can be joined together either vertically (as a cell phone) or horizontally ( as a small book) - depending on how you do so, the two parts behave in different manners. For example, when the display part is vertically joined, the operation part shows a numeric keypad for making a call. When it is horizontally attached, the operation part displays a character entry screen. And it is technically possible to turn the operation part to a gamepad too.

Source