The following--from a discussion at Johns Hopkins during the great structuralism conference in 1966 (!) that took place right after Derrida delivered his "Structure, Sign, and Play" lecture--might help out some of my phenomenologist friends trying to wrap their heads around Derrida. Doubrovsky's great question at least allows you to approach the more structuralist and semiological mode of that essay's articulation:
SERGE DOUBROVSKY: You always speak of a non-center. How can you, within your own perspective, explain or at least understand what a perception is? For a perception is precisely the manner in which the world appears centered to me. And language you represent as flat or level. Now language is something else again. It is, as Merleau-Ponty said, a corporeal intentionality. And starting from this utilization of language, in as much as there is an intention of language, I inevitably find a center again. For it is not "one" who speaks, but "I." And even if you reduce the I, you are obliged to come across once again the concept of intentionality, which I believe is at the base of a whole thought, which, moreover, you do not deny. Therefore I ask how you reconcile it with your present attempts?
DERRIDA: First of all, I didn't say that there was no center, that we could get along without the center. I believe that the center is a function, not a being--a reality, but a function. And this function is absolutely indispensable. The subject is absolutely indispensable. I don't destroy the subject; I situate it. That is to say, I believe that at a certain level both of experience and of philosophical and scientific discourse one cannot get along without the notion of subject. It is a question of knowing where it comes from and how it functions. Therefore I keep the concept of center, which I explained was indispensable, as well as that of subject, and the whole system of concepts to which you have referred.
Since you mentioned intentionality, I simply try to see those who are founding the movement of intentionality--which cannot be conceived in the term intentionality. As to perception, I should say that once I recognized it as a necessary conservation. I was extremely conservative. Now I don't know what perception and I don't believe that anything like perception exists. Perception is precisely a concept, a concept of an intuition or of a given originating from the thing itself, present itself in its meaning, independently from language, from the system of reference. And I believe that perception is interdependent with the concept of origin and of center and consequently whatever strikes at the metaphysics of which I have spoken strikes also at the very concept of perception. I don't believe that there is any perception.
-From The Structuralist Controversy, Discussion of "Structure, Sign, and Play," 271-2
Translating Husserl into the language of structuralism and specifically semiology was primarily the work of Merleau-Ponty (good friend of Lévi-Strauss), and if one reads certain remarks of his from the late 50's you can get a good sense of what that work of translation entails--you can piece together the puzzle that semiology poses to the phenomenologist of the non-French tradition, and begin to read, because all of a sudden you are launched into the types of conversations that were held after his classes there. Suddenly, this more formalized remark of Derrida's--no less extreme in its conclusions--from 1959 might also help, because one understands that it basically says the same thing in a less semiological language:
The question of the possibility of the transcendental reduction cannot expect an answer. It is the question of the possibility of the question, opening itself, the gap, on whose basis the transcendental I, which Husserl was tempted to call "eternal" (which in his thought, in any event, means neither infinite nor ahistorical, quite the contrary) is called upon to ask itself about everything, and particularly about the possibility of the unformed and naked factuality of the nonmeaning, in the case at hand, for example, of its own death.
-"'Genesis and Structure' in Husserl's Phenomenology," in Writing and Difference, 167-8
All this is evidence of the benefits of a historically minded approach to philosophy, which doesn't so much focus on the appropriations and misappropriations of particular philosophers (Husserl or Heidegger), but tries to reconstruct the discourse in which those appropriations are happening. It is also helpful in discussions of Kant, say (who is dealing with the British empiricists and materialists, like Priestley), and Descartes.