One can tell quite a lot about what goes on in a classroom or a school even if one visits after everyone has gone home. Just by looking at the walls--or, more precisely, what's on the walls--it's possible to get a feel for the educational priorities, the attitudes about children, even the assumptions about human nature of the people in charge. In this essay, the author comments on the signs and posters found on school walls and discusses what a person can tell from them about a school. He considers a few signs and posters that are generally regarded as innocuous or even inspiring. Particularly deserving of a closer look are two specific signs as well as a broader category of posters that includes a seemingly unlimited number of examples.