There’s a tradition in Ireland of buying rounds of drinks in a pub. One person buys a round, those on the receiving end reciprocate. It’s very simple — like wash… rinse… repeat — until the rounds extend beyond you and your two close friends.
The very first answer to a student bound for Dublin gives a nice outline of the rounds system in Ireland. Meanwhile, the follow-up comments range from the helpful to the offensive. Have a look for yourself… just be warned, the language used in some of the follow-up comments might offend those who have never spent an evening in a pub
Photo by Cl1kr via Flickr Creative Commons