The previous auction for Queensland flood relief is closed now, but I signed up for two more, so if you lost the previous bid, or you were too late, or it got too high for you, now you have a chance again! :)
For Brazil - here
Another one for Queensland - here
You can also browse other offers and see if your favorite graphics makers (and fanfic writers!) are offering something, and you can offer your own art and fanfiction too!
EDIT: Closed now, thank you so much for bidding! :)