James Sullivan for Cambio
Greyson's challenge? Un-Self Portrait. Watch the video, shot at Cambio's studios in L.A., below for more details, but basically he wants you to take a photo of things that represent you, without actually showing yourself in the photo. Sweet idea, right?
"Say you're really into music like me, you might take a picture of your guitar or maybe even your piano," he says. "Mine would probably be all different pictures from me in the studio, pianos, soundboards, computers... because I spend half of my life in the studio."
Post your photo to Flickr, Twitter, Tumblr or Facebook with a caption and tag them #unwastedweekend so Greyson can see them and pick his favorites to share with his fans. We'll post them on Cambio too.
To check out all the other celebs who have participated in the campaign (there are eight challenges so far), including Karmin, Aimee Teegarden and Tristan Wilds, visit the official Unwasted Weekend page.