From the ever brilliant PSFK:
"When we were in London a couple of weeks ago, Jeremy Ettinghausen of Penguin books was kind enough to give us a new edition of Oscar Wilde's The Picture of Dorian Gray and Magic Tales from the Brothers Grimm. The interesting part: the covers are blank and the owner is invited to draw his or her own cover. They're part of the MyPenguin series and the back of the book announces, "Books By The Greats, Covers By You".
Penguin are also asking people to send scans of their covers to an online gallery here. As you can see from the above, we've still got to get to the book - we were thinking, wouldn't it be nice if after we finished the book we'd leave an image that was inspired by the book, then we'd pass the book on for someone else to read and leave their own mark and so on and so on..."
Here are some examples which you can see here.
You can imagine something like this working for any number of our brands which are often bought as gifts.