In 2006, Hero Initiative and Marvel Comics sponsored the Spider-Man 100 Project. Marvel published a bunch of Ultimate Spidey #100 with blank, card stock covers. Hero Initiative contacted artists to create original drawings on those covers. Those comics were auctioned off at various conventions and on eBay. All proceeds, including from a trade paperback collection, went to The Hero Initiative.
This year, they are doing the Hulk #1 Project. I got my copy of Hulk #1 at MegaCon last week. Since I did a Samurai Hulk short story for the Marvel Underground anthology, I thought I would continue that concept for my cover.
The back cover is pretty clever, too.