I don't have a bookcase or bookshelves, but I do have a fair amount of books. In my bedroom, I store them by stacking them and propping them up on my nightstand. In my living room, there's a ledge where I set my coffee table books with their covers facing forward. I've also learned to use little odds and ends, accessories, and books themselves as bookends. I actually used to simply stack my books on the floor in one tall, wobbly column. Because I'd rather not take up more space with a bookcase, I just make do without one.
How about you? Do you store your books on a real bookcase or bookshelves? Or do you keep them on a table or somewhere else?