Yuan Works, the developers of the upcoming Dreamcast game Wind & Water: Power Battles are offering custom sprites for another 12 hours from now: Send them a photo and they’ll draw a sprite which then you’ll be able to use in the game.
More info: http://www.wind-water.net/order_sprite
The game is available for preorder at redspotgames and Play-Asia.com.
(thanks to vidgames.de for the news)