In an effort to expand the lexicon just a little bit, might I suggest, "piss on a screwdriver," for your future insult needs. While a bit out of the way for most folks, I think it might cover many conversations with mechanics, repair men, and most any other mechanical fix-it persons that you might encounter. While not as colorful nor representing the shear amount of futility as, "piss up a rope", I feel this phrase has earned a place in our language and needs to be given it's due. Feel free to use it when your brake job or dryer repair amounts to over $800. Let them know how you feel about their mechanical ass-reaming and suggest that their tools could be used to better effect.
No need to thank me,
Doc
