well...that reminds me to finally ask: I usually 'get' most references, even when I don't use them, but I have seen "taking the piss" used here many, many times, but even in context I have never been sure exactly how to translate it. (In the US, we may not use it because it is so close to "taking a piss" ...but maybe we simply have another expression already...

Could someone elucidate? And what mught be the origins of such a non-obvious expression?