Other than it's literal meaning, it is metaphorically used to denote somebody being taken for a fool. Mostly used by Brits. Brought to the wider audience by Guy Ritchie's movie, Snatch.
Turkish: (looks at the caravan) Look at it. How am I suppose to run this thing from that? We'll need a proper office. I want a new one, Tommy. You're going to buy it for me.
Tommy: Why me?
Turkish: Well, you know about caravans.
Tommy: How's that?
Turkish: You spent a summer in one, which means you know more than me. And I don't want to have my pants pulled down over the price.