The exhibition web site for Edward Hopper, from the Museum of Fine Arts Boston, features a slideshow of a dozen of Hopper's paintings, and a digital version of one of the artist's sketchbooks. Some Hopper paintings, for instance Nighthawks, 1942, have been reproduced so many times and in so many formats - posters, prints, t-shirts, coffee mugs - that they have become iconic and these are included...