Talk Directly into the Credit Card Please
There's a reason identity theft is one of the fastest growing crimes... it's relatively easy to do for people without any criminal expertese. A discarded bank statement, a rejected credit card application, just knowing someone's mother's maiden names (how many relatives know yours?), by these little things identity theft is perpetrated. Voice-related biometrics may be the answer.
Biometrics is often associated with retina scans and fingerprint locks, but voice-verification is in the works and would increase phone security (i.e. if someone tries to buy something over the phone using your credit card, but isn't using your voice, the purchase will fail).
More information on how the technology will work and when you can expect to see it at Business Week's May I See Your Voice, Please?