FAIL: Find The Error On This School Billboard
On the Internets and among the cool kids, "FAIL" is (in the broadest sense) the new "owned" (or pwned or doh!) as an expression of mishap, failure, humiliation, etc.
Unless I've got this Internet meme all wrong, in which case I'm sure one of you will FAIL! me.
In any case, there's a blog (of course) and it has pictures of things that have gone awry. Sometimes they include school-related content.