BookCrossing (also: BC, BCing or BXing) is defined as "the practice of leaving a book in a public place to be picked up and read by others, who then do likewise." The term is derived from bookcrossing.com, a free online book club which began in order to encourage the practice, aiming to "make the whole world a library."
Book Crossing 是這麼玩的:首先挑選一本要去流浪的書,到它的網站上登記,取得一個書的身分證號碼,然後做一張貼紙,貼在書的封底或任何醒目的地方,接著就是把書放在有可能被人發現的地方,公園的椅子上,咖啡店或是人潮來去的車站。任何發現它的人都可以帶回家去慢慢閱讀,也希望閱讀之後,到這個網站鍵入書的身分證號碼,可以找到這本書的流浪路線和前手的感想,也可以分享自己的心得,並且繼續這一本書的旅程。