Perhaps inspired by the James Bond sniper rifle that can only be fired by Bond, researchers in Finland have created a method for you mobile device (a phone most likely) to ‘recognize’ you by the way that you walk.
In the method, sensors measure certain features in the person’s walk and these are compared to values stored in the memory of the device. If the values differ, the device requests an access code. In trials, the method has achieved a success rate of 90%. VTT is applying for a patent for the solution.