Maxis and EA are running a YouTube Spore Dance Off Contest. All you need to do is:
1. Download the Free Spore Creature Creator
2. Create a creature and animate it with the best dance moves
3. Upload the video to YouTube and register into the competition.
You've got until the 1st of August to register and the finalists will be picked on the 18th. Finalists will then be judged by popularity on YouTube to determine the winner and two runner-ups.
Not really much detail on the actual prize but apparently it's a trip to the Smithsonian Institute in Washington D.C. (guess it's not much of a prize if you live in DC)!