A standard UK pint glass is actually around 1.8 times greater in circumference than in height, but you'd never guess from looking at it.

So when you are next in a pub, bet someone that their drinking vessel is further around than it is high. If there is a 'pot' beer glass (the ones with handles) in the pub, then you're sorted: they are typically three times as far around as they are tall, so you can dramatically stack two of them and claim it is still further around than up.

Producing a tape measure at this point may cause your victims to question the spontaneity of the whole exercise, so use a nearby straw as a makeshift ruler.

If you'd like to subtly check your drinking glass, try to wrap your hand all the way around it. Your fingers and thumb will not meet on the other side. But place your hand on the side of the glass and it'll probably reach all the way to the top.