I've always liked to mess with people in my auto-replies. We should definitely have auto-replies for more human situations than absence from the office and customer service confirmation.
"Thank you for writing. Your message is important to me. I respond to every email in the order in which it was received but if you have any pressing questions please call directly."
Bad Ex-Boyfriend Auto-Reply:
"You've reached a girlfriend who is no longer listening to you. Move on. If this is an emergency, please contact another ex or your mother."
Good Ex-Boyfriend Auto-Reply:
"I am currently away on vacation. Yeah, uh...vacation. Not a new man. A vacation... Let's talk in a couple months?"
Bad contractor's Auto-Reply:
"I am currently on vacation in your offices. I will have only sporadic interest in checking my emails from you and will not make myself available for anything other than group takeout orders and my bonus check. Thanks in advance for the job."