Along with these videos explaining the Crown and battle systems, Square Enix also sent word of a Final Fantasy: 4 Heroes of Light contest that they’re running from now until October 22nd. The gist of it is that you need to design a new Crown for 4 Heroes of Light, complete with its own ability set. You can read more about this here.
The contest is open to those with a Square Enix Members account, and there’s a Nintendo DSi and free copies of 4 Heroes of Light on the line if you’re interested in trying your hand at crafting a Crown. The first prize winner also gets a framed picture of his/her crown drawn by the game’s Crown designer, Yuka Miyamoto.