The Second Annual Draw Muhammad Day is May 20, 2011! No, it's not an effort to make fun of a religious group or be disrespectful. It is, in fact, a day to condemn blasphemy laws and call on religious people to respect the rights of everyone, not just their own adherents. In the USA, it's a celebration of our First Amendment as well. It could just as easily be Say Jehovah Day - the point is the same.
For more about the day, see this blog entry by the Friendly Atheist.