Try this:
"Speaking of p.enises..."
and hung up.
I was seriously confused and said "Eh? What? Who said anything about that?!?"
When I called her back, she was dying of laughter and explained where that came from:
She was in school at lunch and she and her friends were discussing the "natural thermometers" and how the human body reacts to cold; some how the subject goes to German sausages (Food.) Then, she paused and said "Speaking of p.enises..." and left for class.
She told me to do the same to my brother.
It was hilarious.
Now, I want you to try it.
Be sure to pick the right victim:
They should be confused, stunned and possibly embarrassed by it.
Be sure to play it right:
Right after you say it; walk away, hang up or do what ever you can to avoid your impending laughter breaking the utter confusion.
Pick the right environment for the joke. You obviously can't walk out of the room if you're in a car on the highway...
Post your list of reactions to it here.