An interesting idea for books?

Over on last100, they have an interesting article on Peter Gabriel's website The filter, which is described as:-

The Filter is the ultimate discovery service. Tell it the movie, music and WebVideos that you like and it will find new stuff for you that match your taste – every day.

An interesting idea, which could certainly be extended to books (though everyday might be difficult to do). It would certainly help with serendipitous searching.