What would be good (though not very likely) would to have it so the book change overs have to be done in person.
When the book changes hands a photo needs to be taken and then posted to a website.
That way we get :
1- To see who has the book
2- To see the condition of the book at each point (we can see who damages it)
3- rid of the possibility of it being lost in the post.
4- To know where to find the book if it stops getting passed about.
