There is a online site thats quite fun Magoo.
ermm will see if i can find it again - wait there
YAY - sometimes my memory works for me.
http://www.bookcrossing.com/BookCrossing is earth-friendly, and gives you a way to share your books, clear your shelves, and conserve precious resources at the same time. Through our own unique method of recycling reads, BookCrossers give life to books. A book registered on BookCrossing is ready for adventure.
Leave it on a park bench, a coffee shop, at a hotel on vacation. Share it with a friend or tuck it onto a bookshelf at the gym -- anywhere it might find a new reader! What happens next is up to fate, and we never know where our books might travel. Track the book's journey around the world as it is passed on from person to person.