Rebekah:

Thanks for defending my metaphor, Sharn!  Nick, here are some others you might not have heard: 

A couple of my dad's were

"Kangaroos in the top paddock"  for people he considered "nutty"

And for anyone he considered a poor driver (my dad was a policeman so he was able to trot this out quite often) WARNING: Considered crude in polite company: "couldn't drive his finger up a soapy dog's backside"