(500) Days Of Summer co-stars Joseph Gordon-Levitt and Zooey Deschanel have treated fans to a special duet to celebrate the end of 2011.

The actors/singers have filmed a video of themselves performing a cover of Nancy Wilson's "What Are You Doing New Year's Eve," with Gordon-Levitt on guitar and Deschanel on a ukulele.

The clip has been posted on Deschanel's blog HelloGiggles.com and is accompanied by a sweet note gushing about her friendship with and admiration for the actor.

She writes, "I have known Joe Gordon-Levitt for going on 12 years. We first met in the summer of 2000 while doing a tiny movie called Manic, where we bonded over a mutual appreciation for Harry Nilsson and Nina Simone and I have been lucky enough to call him one of my dearest friends ever since.

"When we did 500 Days of Summer 8 years later, we spent every lunch hour dancing to Marvin Gaye in the hair and make up trailer; we had loads of fun. I hope to do a thousand more movies with him because he's simply the best. But, in the meantime, we made a little New Year's duet for all of you! The original by Nancy Wilson. ENJOY!"