book crossings

I know a lot of people do this, leave a book they love behind on the bus, or train, or subway, with the intention that somebody else should also enjoy a book we've enjoyed. Now, if it matters to you, via urbanist , I found out about a way that those to whom this matters, can track the journey their book takes once it leaves your hands.

Anyone who has a book that they liked but don't want to keep is encouraged to register it at BookCrossing.com, write a note in the front, with the "Book Crossing ID," then leave it somewhere where others will find it.

Seems like a fun idea.