I'm sure this has already been mentioned, but it's pretty funny that in the UK we use Stones to measure weight.
My wife, who is from the US, was particularly confused when she first heard this. She asked me what the excess stones were called (if, for example, you weighed 12.6 stones) and I said pebbles. It was obviously a joke, and I forgot I had even said it.
Months later I find out she's been telling a bunch people that in the UK we measure things in stones and pebbles like primitive medieval folk.
As an American, I still have no idea how much a stone is. But any time some one uses it, I immediately picture them as a gigantic burly Scottish man in a kilt