In reply to gravy:
not really paid any attention to it - but was that also a bit of augmented reality/HUD style application? not really what I'm after.
To give you an example - I teach people how to intubate dogs, but its really hard to see what they are seeing during the task and so give effective feedback - being able to stream an image from a camera sited between there eyes to a phone or tablet would let me give much better feedback/guidance.