While doing valuable research (which might one day grant me an income which doesnt make me cry), i saw that google has more hits for 'beta' than for 'alpha'. I wondered a bit and did a small survey which led to the following figure:
Figure1. Google hits for the indicated search phrase representing greek letters. If the top ranked search result was not the wikipedia article, a short description of the top hit is given above. The queries were send 2011.3.23 14:00 (GMT+9)
