An excellent example of a joke about race (well, ethnicity, but the same basic conversation): Years ago, there was a Polish sports figure (I believe he was in football) who had a TV commercial for some product or other. In it, he said, "Sometimes people ask me what I think of Polish jokes. I'll tell you, I love Polish jokes! They're my favorite. Here's one, for instance..." and proceeds to tell a joke in Polish. It was a classic meta-joke, because on one level it showed him turning the prejudice on its ear, and on another it played off the "clueless Polack" stereotype (i.e., he was too dumb to know what a "Polish joke" was).