Judging by the size of the device, I'd say that this is likely a good source for the physical specs of the people using it: http://www.bodybuildingpro.com/bestbodybuilderever.html

Seriously, that thing is huge, and is easily larger than anything I needed to carry for an upper-division math class, other than the 'Advanced Engineering Math' course. The book for that was so expensive because it came with sherpas and a mule team. But I digress...

I'd like to see how they avoid the doom of nearly every other attempt at electronic textbooks: publishers that are totally unwilling to distribute their books in electronic form.

Apple and Amazon have enough clout between them with the Kindle and iPad to bring the heavy guns to the negotiating table; the verdict on the Kno remains to be seen.

Updated my comment with a link for you.