To some it's anathema, to others it provides relief from crippling pain: to others still, it is a legal anomaly and should be decriminalized. Whatever the viewpoint, and by whatever name it is known, cannabis - or marijuana, hashish, dope, kif, weed, dagga, grass, ganga - incites debate at every level and its impact on the world's cultures and economies is undeniable. Dating back to the Neolithic period, the history of cannabis is a tale of medical advance, religious enlightenment, political subterfuge and human rights; of law enforcement and customs officers, cunning smugglers, street pushers, gang warfare, writers, artists, musicians and happy-go-lucky hippies and pot-heads.