Call it pot, marijuana, grass or skunk; the way we smoke cannabis is changing. Once confined to hazy student dorm rooms, its use is increasingly out in the open. From complete legalisation in Uruguay to the steady increase of medical and recreational marijuana available in the US, cannabis has become widely available in many places. John Walsh, director for drug policy and the Andes at the advocacy group WOLA, joins us this week to take a look the progress, and the problems, of the legal high.