I joined the library today! I'd highly recommend it to anyone in Barcelona. It was easy to sign up for a card online and then pick it up the next day. This is the first time I've been a member of a public library since I was 9, because at age 10 I moved to a library-less "village." Sadly the branch I went to was slightly smaller than my high school library, but they do have a nice outdoor patio, free weefee, lots of CDs, and pretty liberal lending policies ("if you think you might need these more than a week, just call us and let us know!").