I intermittently read a webcomic xkcd, which is mostly teccy and sometimes mathsy jokes. One from a couple of weeks ago stikes me as funny: “Math Paper“. Also, the last frame reminds me of a sign I saw attached to the side of the Department of Mathematics at Bristol. I took a picture of this, (I didn’t take much time over this as it was raining pretty badly so the quality is not great, but I think you get the idea):

(for those grounded in reality, the sign was of course in the car park attached to the Department).