I think this may be my new favorite blog: "Weird Things Customers Say in Bookshops"

One example:

Customer: Excuse me, do you have any signed copies of Shakespeare plays?
Me: Er... do you mean signed by the people who performed the play?
Customer: No, I mean signed by William Shakespeare.
Me: .....*headdesk*

You should check it out... you'll probably get a good chuckle =)