bookcrossing: n. the practice of leaving a book in a public place to be picked up and read by others, who then do likewise.
(added to the Concise Oxford English Dictionary in August 2004)

That's from a fascinating site I just discovered, http://www.bookcrossing.com - The World's Biggest Free Book Club - Catch and Release Used Books. The site explains:

Welcome to BookCrossing, where 600,813 people in over 130 countries come to share their passion for books with the world.

At BookCrossing, you can register any book you have on the site, and then set the book free to travel the world and find new readers. Leave it on a park bench, at a coffee shop, at a hotel on vacation -- anywhere it might find a new reader! Track the book's journey around the world as it is passed on from person to person.

Help make the whole world a library and share the joy of literacy.

members: 600,816
books registered: 4,307,482
good karma: priceless

Whoever finds the book can contact the site, and you'll be sent an email letting you know where your book has gone.

I'm looking forward to trying it!

There's another site called Book Mooch.

[Fixed typo to cunctate seizures.]

This message has been edited. Last edited by: zmježd,

We discussed this a couple of years ago here.

Yes, and when we discussed it for some stupid reason I joined the site. I kept getting email after email from them, even when I'd click the link for stopping them. I think I am finally rid of them. Sign up only if you're very interested!