This probably came up on the geek at some time – but it's new to me. Fascinating.
From their site: TileToy is a modular, electronic game prototype for tangible LED game tiles. TileToy brings the flexibility inherent in digital software to a physical tile that people can touch and interact with. By arranging the electronic tiles, players can engage themselves in various kinds of game play, ranging from fast-paced arcade style games to puzzle an learning games.
What I also find fascinating is the potential to embedd dynamic graphics under something more constant and textural to provide thematic grounding. Very interesting way to layer information. For example, LED under a tile or map just as the LED shows through the veneer on this block of wood clock.