Awesome ebay auction that I randomly stumbled upon:
About a decade ago a local public libraryswitched from the old library card catalog file system of looking up where to find books in the library, to a computer system of doing so. Instead of throwing out all the old cards the head librarian saved a few and sent them to the author who wrote the book listed on it, asking the author to autograph the card and send it back to the library so they could sell the cards as a fundraiser.
Most authors didn't respond.
Kurt Vonnegut did.
I'm not certain that Vonnegut would approve of the price tag, but it's a cool item nonetheless.