How to talk about books you haven't read

I found How to Talk About Books You Haven't Read (by Pierre Bayard, Granta, 2008) on the sale table at the bookstore on the weekend, and couldn't resist taking a peek inside. By the end of the first page, I was hooked. Written by a professor of literature, it begins with the premise that there are millions more books you have never read and will never read than you have actually read or will read in your lifetime. Of necessity, you will therefore spend the majority of your life talking about the plethora of books you have not read.
He further categorises books into four categories: books you have skimmed (encompassing most of the books you've read), books you have heard of, books you have read but entirely or partially forgotten, and unknown books. Bayard is French and unsurprisingly leans towards a Derridean theory of reading, espousing the postmodernist precept of multiple readings of any given text. That's a concept I particularly like, since it would be a boring world indeed if we all got exactly the same meaning out of every single shared book (although it would certainly save time in our household, in which one or the other of us is generally to be found loyally but disappointedly ploughing through books recommended by another member of the family -- the phrase "you MUST read this, you'll love it" is almost never, in our experience, true.)
Bayard says that you can say a lot about books you haven't read, just by being able to place them in your personal library. If you know what books they'd be filed next to on your mental shelving, for example, you can learn a lot without ever opening the cover. For instance, I just bought Ransom by David Malouf (which is presently a book I have heard of, but I hope to make it a book I have skimmed soon). I have read other David Malouf books (although it was some time ago), so I'll mentally shelve it with The Great World (a book I have mostly forgotten). I know it's a retelling of the Iliad, so on its other side I'll shelve the original Iliad (in translation, a skimmed and partially forgotten book), as well as other Greek literature, mythology and history (skimmed, heard of and wholly or partially forgotten). Thus, without having read past the cover blurb, I already know a great deal about what the book is like and can attend the Writers' Week seminar with impunity.
Isn't that fantastic! Think how much time and stress you'll save now that you know you don't have to read your next book-club book before you get to the meeting! I feel so free...