Yes we recently trotted down to the Santa Monica Public Library got a library card and haven't looked back since. We try to go every Monday to replenish our stock of design books, new novels, garden inspiration and how-to's and they even have dvd's and it's all free! We know, we didn't believe it either.
How is it green? Well, it might be obvious, but we'll spell it out: instead of buying a new book, you're renting one that tons of other people will read too, so you not only are cutting down on new books being printed, but you're creating space in your home by not having an overflowing bookshelf. You can therefore live in a smaller space, or just be happier (like we are) living in the same space but with less clutter.
So have you been checking out the library? Anyone do book swaps with friends or through services?