File this under the category of do-it-yourself politics. In this YouTube.com era, it was only a matter of time before it happened. MoveOn.org has joined forces with Oscar-winners Ben Affleck, Matt Damon and Oliver Stone, multiple Grammy-winner John Legend and author Naomi Wolf to a TV ad contest for Barack Obama. The contest is called "Obama in 30 Seconds," in which Barack supporters are being asked -- challenged -- to come up with half-minute videos that focus on what it is about the Senator from Illinois that inspires them. The winning entry will be shown on national television.