Drivers will be able receive turn-by-turn directions should they get lost. They will also be able to dictate faxes and e-mails while on the move.

And it is not just car-drivers who will be able to lay claim to a "smart" vehicle - the system can also be installed on motorbikes and scooters.

Developed by the London-based firm Skynet 2001, it combines mobile phone technologies and what is known as global positioning system.

The package has two main components. The first part, called Skamp, is a security and vehicle tracking system.

Skynet has been fitted to 250 cars

It enables operators in Skynet's monitoring centre to see the exact location of the vehicle, and speak to the driver if a car seems to be being stolen.

If the driver is unable to supply a unique Pin number, the operator can stop the car's engine if it is safe to do so. Alternatively they may call the police and tell them exactly where the rogue vehicle is.

Skamp is also fitted with sensors which detect the sudden braking caused by an accident. An operator then speaks to the driver and alerts the emergency services if all is not well.

Drivers can telephone the monitoring centre to have the car door opened should they lock their keys inside.

Hotel rooms booked

They can even call for help to find their vehicle should they have forgotten where they have parked - so long as they can remember their Pin.

The second part of Skynet's system is the Executive Vehicle Assistant.

Subscribers to the EVA service can use Skynet's hands-free phone link to dictate messages, receive directions and even book hotel rooms.

At the moment this is taken care of an operator, but the company hopes that improvements in voice recognition software will eventually lead to the whole process being automated.

Two hundred and fifty of Avis Rent-a-Car's London Heathrow Airport fleet are being fitted with the system.