The BBC's Sue Nelson: "Encoded parts of the iris are more individual than a fingerprint"

The new machine, known as Stella, has just gone on show in London following a successful public trial in Canada. It does not use a keyboard, and could see the demise of customers having to remember Pin (Personal identification number) numbers.

It gets to know a customer personally - even down to remembering birthdays - through the recognition of his or her iris, the coloured part of the eye.

The customer stares into three, high definition cameras, which identify the user by scanning 256 points on the iris. The method is virtually foolproof, and is more individual than fingerprinting.

Financial services

Chris Hughes from NCR Financial Solutions said of the new development: "In future, it will be able to provide you with information on car loans, mortgages or sort out your personal financial affairs."

Meet Stella: The cashpoint can even wish you a happy birthday

The chances of Stella making a mistake are said to be 10 billion, billion to one.

Richard Tyson-Davies, from the Association for Payment Clearing Services, said any method that confirms that the customer is the correct customer "has to be welcomed".

This latest development in cashpoint convenience follows moves to install them in nightclubs. The machines would also be able to provide clubbers with airtime cards for pre-paid mobile phones and stamps.