Here is the lovely and charming Mr. Stuart Ashen to give you the details and an example of what you can do:
If you can't see the video you can get the essential information from the Challenge information page. Now, this is a London contest running on United Kingdom time. They gronk UTC and BST so if you don't want to be left out then you'll want to confirm entry time with a site like TimeAndDate.com.
1:00 p.m. London BST is 8:00 a.m. in Grist Fiord, Canada and 5:00 a.m. in San Diego, USA.
My understanding from the video is that it doesn't necessarily have to be a talking head video but since you only have 48 hours you aren't going to recreate Forbidden Planet either.
There are prizes but the really the good stuff is going to come from the videos and the creativity behind them.
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