Enno de Kroon is an artist from The Netherlands who paints on egg cartons and has totally blown me away with his whole concept of two-and-a-half dimensional art. When viewed at an angle, his paintings provide a totally different perspective than the frontal view that's shown here. This is how he describes his choice of canvas and the viewer's experience:
"As a painter I consider egg cartons as two-and-a-half dimensional objects which offer me remarkable possibilities for imagery. The waves of the egg cartons limit the viewer's perception; they also make him aware of his positioning towards the image. The intentional limitation in subjective perception gives room for imagination and recall: the process of occlusion. By a fusion of direct and indirect perception conventional imagery is overtaken. At first sight this leads to a physical and mental incompleteness, that forces an integration which can only take place within the inner experience, apart from time and space."
His Flickr profile is full of fascinating glimpses into the amazing work he calls Eggcubism and the process it entails. You'll be missing out if you don't make a stop here yourself.