From page 26 of 1984 by George Orwell:
"He took a twenty-five-cent piece out of his pocket. There, too, in tiny clear lettering, the same slogans were inscribed, and on the other face of the coin the head of Big Brother. Even from the coin the eyes pursued you. On coins, on stamps, on the covers of books, on banners, on posters, an on the wrapping of a cigarette packet--everywhere."
I've read this book several times in the past. With all the symbolism, it's easy to rouse interesting thoughts concerning 1984. I find this particular quote necessary to the plot of this novel because it emphasizes the fact the Winston was living in an environment where all forms of communication are controlled. America would be a land of chaos if the government forbade us to write. In 1984, Big Brother utilized writing in two ways to controll the citizens of Oceania--one, to make himself and his message present everywhere as this quote represents, and two, to restrict the citizens from individualism, which writing greatly promotes.
At one point earlier in the novel, Winston asks himself while preparing to write in his beloved diary, how the world is supposed to communicate with the future. One would think the answer is easy in a literate nation, but for Winston writing was punishable by death, so why would one risk death to communicate with the future?