Dos cosas

La primera, en la frente, que es de don Ignacio:

Dos amigos judíos en una estación. “¿Adónde vas?” “A Cracovia”. “Eso dices para que yo crea que vas a Varsovia. Pero no me engañas. Tú vas a Cracovia. ¿Por qué no has dicho la verdad diciéndome que vas a Varsovia?

La segunda donde ustedes quieran, que es de Futility Closet:

Scottish writer Alasdair Gray is a practical joker. As his collection Unlikely Stories, Mostly was going to press in 1984, he called publisher Stephanie Wolfe Murray and said, “I want to have an erratum slip inserted.”
She said, “Oh God! What’s wrong? Surely we corrected everything. What do you want to say on it?”
He said, “I want it to say: THIS ERRATUM SLIP HAS BEEN INSERTED BY MISTAKE.”
“Of course we said yes immediately,” remembered Wolfe Murray, “but it was a hell of a nuisance, having to get it inserted into every single book, and expensive probably, but well worth it. All of us thought so.”