The English translation of "La trahison des images," the true title of the painting. Painted in 1929 by the Belgian surrealist René Magritte, this is a profoundly simple piece of art. It shows a brown smoking pipe on a brown background, subtitled with the French sentence "Ceci n'est pas une pipe" -- "This is not a pipe."
Confused? Don't be. Magritte's point was simply that a painting is just an image of a thing, a representation of it. When asked why the image he had painted was not a pipe, Magritte reportedly responded: "Because I can't use it as a pipe." Perhaps as a surrealist he'd been told one too many times that his paintings didn't represent reality, or perhaps he just wanted to comment on the peculiar uses and abuses of ordinary language.
You can see it at http://french.chass.utoronto.ca/fcs195/surrealism.html . Or rather, you can see a picture of it -- Ceci n'est pas une peinture.