I really like these, they would be really nice in a small room where there may not be room for a book case. You could make them with only 2 or 3 shelves and then a dresser or other piece of furniture could still go against the wall below.
I think they would be nice if you had toddlers as well. You could still display your treasures without worrying about them breaking them. Timpaslay has the instructions over on Instructables.
http://www.instructables.com/id/How-to-Make-Suspended-Shelves-with-Steel-Cable-and/?ALLSTEPS
