Mind-reading Interfaces
The Neural Impulse Actuator, by OCZ Technology, lets you interact with the contraction of various face muscles. From Wikipedia:
The name Neural Impulse Actuator implies that the signals originate from some neuronal activity, however, what is actually captured is a mixture of muscle, skin and nerve activity including sympathetic and parasympathetic components that have to be summarized as biopotentials rather than pure neural signals.
So I'm a bit confused myself on whether to call this a 'mind-reading' interface or a 'muscle-reading' interface. Perhaps it's something in-between. What is clear is this genre of interface appears commercially viable for the mass market; sold first as hardcore gaming interface, later to infiltrate mainstream OS usage. This is a whole new world of Interaction Design.
A nice intro to what I'd call true 'mind-reading' technology in the following 60 Minutes story: