To most people the word Rastafarian conjures up images of dreadlocks, the smoking of ganja, and Bob Marley. But Rastafari, as it's more correctly known, is a movement with a complex belief system. It has its origins in Jamaican society in the early 20th century, when black people rose up in protest at oppressive systems imposed by white rulers. But is it just a passing phenomenon? Has it continuing relevance in a fairer, more open society? How does it need to evolve?