The official Hatsune Miku Facebook page is asking fans to draw their very own images of Miku (with or without other Crypton VOCALOID characters) so that a few chosen ones could be paraded one-per-day as the official “cover art” for the Facebook page once it reaches half a million likes. In addition to illustrations, photos will be allowed as well. More details on the submission guidelines can be found in the original post.
UPDATE: The official Facebook page has now received over 500,000 likes and has started adding cover photos.