Not actually having used Touch ID on the iPhone 5S yet, I can already think of a great place for it in the future: The power button on Macs.

I realized today how much time it would save me if I could use Touch ID to unlock my Macbook Pro that is issued and administered by my employer. Trying to think of where on a Mac the sensor could go, the power button seems like the most elegant solution and a natural adaptation of the existing hardware. The sides of a Retina Macbook Pro are too thin, as are the Macbook Airs. The FaceTime camera would just get dirty, and anywhere else would stick out like, well, a sore thumb(print).

Desktops could also use their less convenient to reach power buttons, or perhaps the Apple logo could hide the sensor.

If Touch ID is a success for Apple it would be cool to see the capability transition to the Mac line. In the mean time the ability for the Mac to use the iPhones Touch ID sensor would also be a cool trick.