We've just stumbled on the work of Peter and Donna Thomas (via http://www.libraryasincubatorproject.org/), and it's amazing. The pair make books and book-related art in Santa Cruz, California, and we've totally fallen for their fine press editions and miniature creations.
Their work seems to challenge the idea of just what is a book. The two established an independent press in 1976, and according to their website:
At that time their goal was to create books in the tradition of the great private presses: limited editions, made of the finest materials and produced with the highest standards of quality.
Check out their amazing work at: