iPod as a security key?

There are stories going about on how the iPod could pose a security risk. If that’s the case, then make lemonade out of lemons, I say!
After viewing a few interesting shareware programs for personal use, I wonder if anyone’s ever thought of using the iPod conversely as a mobile security key.
In order to access specific programs or data on a computer, an iPod with pre-installed software codes has to be docked and linked to it, acting as the second half of the jigsaw puzzle. I can imagine countless uses for it. Employees in high-security workplaces could carry iPods about town like any other civilian would. You wouldn’t be able to tell these lean mean music machines were keys until you docked them with the right computer and, say, performed a special action on that computer.
To prevent the information from falling into the wrong hands, the iPod’s ability to unlock data could be time-sensitive. Also, the key on the computer’s side could be slightly modified so that docking with the iPod would no longer trigger a release of information.
Does it sound too much like something out of a James Bond movie to you, or am I making some sense here?