Hungarian architect Aron Losonczi has developed a concrete block wallthat allows light to pass through. It is pretty cool that an ordinary cement mixer, some sand, some gravel, and cement will produce something this advanced. It does require well placed optical fibers to move the light from one side of the block to the other, but this is an example of the creative uses that mixers are providing to innovative applications of concrete.  

Thanks to SmartPlanet for the image.