I'm reading "The Da Vinci Code"... very good book, overall, interesting and well-written.
At a certain point of the book, though, the characters wonder about the meaning of an inscription that "doesn't seem to be written in any known language". The book provides an image of the inscription.
And I dunno whether this says something about me, or about the characters, but I pretty much immediately exclaimed, out loud, "sheesh, it's written backwards, you dimwits, find a mirror".
Ah well. At least it didn't take them more than a page and a half for them to figure it out...