(I have no other things to post tonight, but this one couldn't wait; it was overheard while out getting ice cream during during The Hang™.)
"About three years ago, I was taking this introductory physics class, and the professor asked everyone how many pounds were in a kilo. I looked around and saw that nobody had raised their hand, so I shouted out '2.27 pounds!' The professor smiled, paused for a moment, and said, 'Well, at least we always know who the drug dealer is in the class.'"--Dude behind the counter, to some customers.