When I was a small child, I was obsessed with the idea of a message in a bottle (not the Police song)... This is even better...
I recently gave a beloved book to a girlfriend - and it occurred to me that it had originally been recommended to me by a girlfriend, who had been recommended by... You get the picture.
So, we had the idea that - upon finishing the book - my friend should pass it onto someone else. We wrote our names in the inside front cover, and she decided that next she would give it to her sister, with instructions about passing it on.
A chain letter book. I love the idea. I want to keep this going and make more of them!