http://www.newscientist.com/news/news.jsp?id=ns99996092 this shouldn't be too much of a suprise. No need for incredibly expensive equipment either. It is known that light travels slower in denser materials. 'Materials' can include space itself since space consists of quantum fluctuations. Different densitys of these quantum fluctuations may alter the speed of light through it. Since space is reckoned to be expanding then it may be that speed of light is increasing with time. I think loads of people have speculated this at physicforums over the years. At last the experts are listening to our ideas!