A trio of Japanese companies have come together to create the world's first mobile phone that also acts as an electronic key for certain vehicles, allowing its owner to automatically unlock their car door and start the engine without having to fish around in their pockets for a traditional key.

Developed by Nissan, Sharp and Japanese telco NTT Docomo, the new device will only work with Nissan's electronic ‘Intelligent Key’ feature, which has been installed on almost a million Nissan and Infiniti models since 2002.

The convergence of automotive and cellular technologies was made possible by Docomo’s expertise in the marketability of mobile phones, Sharp's development of the phone itself and Nissan's provision of technical support to ensure the key's operability with its vehicles.

The phone was created as a response to the increasing ubiquity of mobile telephones in today's world, and a desire to make the consumer experience as seamless as possible. The mobile phone will be used mainly for automatic keyless entry and engine ignition, lockout prevention, and conventional remote locking and unlocking.

The separate companies will demonstrate their new 'Intelligent Key' mobile phone in their respective exhibits at CEATEC Japan 2008, which begins September 30 and runs until October 4. The three firms will continue to develop the product with an aim for commercial distribution in the middle of next year.