Yes, my Dad always had a few -

"He/She couldn't organise a _ _ _ _ in a brothel with $50"

I am a trainer in IT, and if someone is a smarty pants and says things like "Can I give you a tip" - I usually reply "Let me give you one, Race number 2, Horse number 5".

Or

"Don't Pee into the wind" (I LOVE that one!!)

"One sandwich short of a picnic"

......... great thread!!!