Valve has kicked off a contest tasking punters to make a music video based on The National's "Exile Vilify" song featured in Portal 2, with exclusive prizes up for grabs for the lucky (or rather talented) winner.

The contest started yesterday and will run until midnight July 15th, giving you a month to set up your director's chair and start filming something spectacular to bag the grand prize of a guitar autographed by The National and a collection of Portal 2 merchandise.

To enter, simply upload your video to YouTube, using whatever visuals you choose, with the tag PORTAL2NATIONALEXILE. The winner will then be selected by the community to scoop those lovely prizes, so get cracking on those music videos! Portal 2 is out now.