In today's weekender section of the Wall Street Journal (page 8) is an article titled "I'm a Traveler, You're a Tourist: Please Go Away." The WSJ is a subscription site, so I don't think a link will work. Anyway, it talks about many of things that have been debated on this helpline, such as why Americans hate being around American tourists and why "travelers" think they are superior to "tourists."
One piece of news (at least to me) -- Apparently, there are "heat-maps" on the internet that show where tourists go. They have been created by programmers using data from photo-sharing web sites. Has anyone ever seen these? If I were to use one it would be to figure out where the most beautiful places are, not to avoid my fellow tourists. (Though I might try to go off season.)