Ever wonder why you see some
people playing with their wineglasses before taking a
sip?
Here's one reason: Swirling the wine in the glass coats the whole inside, giving a fuller aroma and with it, a much richer taste.
And now you know.
This, of course, has nothing to do with the people who lick their fingers and run them around the tops of crystal wineglasses to make them "ring". That's just simple resonance.