falling asleep at my desk

I insist that today be a highly productive day. I'm tired, I'm feeling uninterested in what I have to work on (my conference paper), and I am cold. Not such a great combination. Which got me thinking...how many people are falling asleep at their desks right this minute? Probably hundreds or thousands. And for that matter, how many people are mindlesslly surfing the internet or checking thier email? Do offices really breed unproductivity? What would the human race look like if we were able to concentrate better?