A friend of mine asked tonight what Rastafarianism is. We had just heard some semi-reggaeish music on a PA system. I had to tell him I didn't know much about it. Without looking it up on Wikipedia or a more specialized source I can tell you that the central Deity is basically the Judeao-Christian-Muslim God, that Africa is treated as the Holy Land, and that while a lot of worshippers are based in Jamaica, it's not the majority religion in that country.
Also, if I were to greatly increase my marijuana intake and buy a red-green-yellow knit hat, that would not make me a Rastafarian. It's a little stricter than that.