A new Japanese mobile phone will automatically unlock the doors of its owners' cars and let drivers start their engines without using an ignition key. The phone, built by Sharp Corp., uses a technology previously developed by Nissan Motor Co. called "Intelligent Key" that allows drivers enter and start their cars without removing their keys from their pockets or bags. Cars equipped with the system sense when the correct key is nearby, automatically unlocking their car doors, and allow the engine to be started once the key is brought inside the car. Nissan said it has shipped about a million cars with the technology in Japan since 2002. The new twist on this technology is that it is loaded in a phone. The service will work on the mobile network operated by NTT DoCoMo Inc., Japan's largest mobile operator.

Personally, I wouldn't ditch my keys just yet because with my luck, I'd end up locking my phone in the car. I wonder if they gave much thought to the fact that if you lose your phone you could end up having your car stolen too ;-)