"Mann, a 41-year-old engineering professor at the University of Toronto, spends hours every day viewing the world through that little monitor in front of his eye - so much so that going without the apparatus often leaves him feeling nauseous, unsteady, naked.

The wearable computer allows me to explore my humanity, ALTER my consciousness, shift my perspectives so that I can choose - any given time - to see the world in very different, often quite liberating ways," he wrote in "Cyborg".

For example, Mann and his graduate students have developed software that can transform billboards or other rectangular shapes in the physical world - when viewed through the lens of a wearable computer - into virtual boxes for reading e-mail and other messages."