Screw HMDs! Go for contact lenses!
Okay, I have to admit, this is a bit unfair. I’m waiting for slim HMDs like all AR enthusiasts. But there will still be restrictions, speaking about field of view, still the need for a device stuck to your nose, that can slip and destroy the overlay-position, etc. But in a future, far, far away, we could be able to get rid of our then-old cyberglasses and swap them for cyber contact lenses! Over a year ago, technology review already covered this topic on research at Washington. Now, fresh online, a detailled report on this emerging technology, written by Babak A. Parviz can be found here. Intereseting read, while we are waiting for the new iphone OS or new layar-layers. ;-)