Keith Haring's brilliantly instant paintings and images are some of the most recognizable of any artist, ever. Out of all the artists that emerged from the New York graffiti scene in the late '70s and 80s, it's Haring who has had the greatest pop impact. Today his work has acquired extra relevance - Haring was an early and very vocal exponent of diversity who fought all forms of prejudice through his art. He was, and remains, universally loved. In...