The bio knob offers a cool convenience: it allows you to unlock doors using your fingerprints, but it also potentially allows users to track when a 'spouse or teenager' came home.  If this kind of passkey becomes commonplace, is it yet another example of our perpetually trackable, surveillance society?

http://www.tychisystems.com/

Plus, test your senses with this cool BBC online quiz!  Tell us how you did!

http://www.bbc.co.uk/science/humanbody/