For those interested in learning about the subject, here's a good place to start (in order):
Ferdinand de Saussure, Course in General Linguistics http://books.google.com/books?id=B0eB8mvov6wC&printsec=f...
Jacques Derrida, Of Grammatology http://www.mohamedrabeea.com/books/book1_3997.pdf
and, for fun...
Jacques Derrida, Differànce http://hydra.humanities.uci.edu/derrida/diff.html