Jonathan Lethem's essay "The Ecstacy of Influence" was published in Harper's Magazine back in late January, which makes it ancient in the compressed timeline of blog chatter. And it has been fully chattered over, mostly because it is brilliant, so I won't say much. I'm just posting it as a reminder to myself, and for anyone who didn't manage to see it. It is an articulate and ingenious manifesto about the way borrowing from others' work is not just common to writing, music, art, etc, its fundamental, unavoidable, and of great value. This makes the copyright obsession with distinguishing new work from borrowed untenable at its core.
Plus there's a twist at the end worthy of The Sixth Sense and Fight Club.
Here is Henry Jenkins' lucid discussion of the piece.