Working a full eight hours with maximum productivity is an impossible task. Real work takes a maximum of one hour of intense concentration and that is it, you are free for the rest of the day, unless you are in the army and need to stand at your post to guard against foes and allow friends in, or possibly you work on an assembly line and need to see each little piece of equipment as it passes in front of you on the conveyor belt, or you are a call center agent and receive random calls from random people, or you are a student and in that case there is never enough time.
The rest that work in a bureaucratic establishment know you need to shuffle a few papers; read a few reports and scribble in some comments and do nothing for the remaining seven hours.
How do you spend that extra time? Before, pre-internet, it was by reading all the daily newspapers, followed by calling all the classified ads that interested you, then visiting the offic diwaniyah (meaning the colleague that had the best office with the most seats and farthest from management).
Well that was then, now you just surf the net, catch up on your emails, and talk on your instant messengers. I am happy to anounce that it is also completely legal at least in New York.
So browse away safely in New York, and if you are not in New York, be sure you have your work related application active in the backgroud so when the boss passes by, you can quickly jump to it.