I was looking at the small Pbook collection I've gathered here in Berlin, and a thought came to me.
Today and in the old days, you could tell a person's taste for arts if he or she kept a large collection, whether of pictures, vinyls or CD's... or books, if your character was a bookworm.
To come with an old example, the Quixote posessed an expanded library for the sake of whose expansion he had sold even part of his estate. Moreover, the titles of the books he read, which are revealed when his neighbors enter inside it and begin to sort out the "malign" ones, show us his madness and folly about chivalry books.
In the 21st century, it would seem that physical collections will recede, even for bookworms. Plus, you can't tell a person's tastes right away anymore if he or she merely sports an mp3 player or an ebook reader, for they're mainstream devices which can be used by either casual readers or hardcore users.
How will we identify the bookworms of the 21st century in contemporary novels

?