In her first nude scene, Karen Gillan (Amy Pond in Doctor Who) shows butt in the romantic comedy Not Another Happy Ending, which is now available on DVD and VOD in the UK.
After her character's agent suggests she she try writing naked, Gillan is shown completely naked from the side sitting in a chair with a laptop on a table. Her breasts are covered up, however, by her hair and arms. After getting up to see who is at the door (nothing below the shoulders shown), and then answering the phone, there is what would have been a full-frontal shot blocked out by a lamp. There is then a full ass shot as she rushes to take something out of the oven. There is a shot of her face from the side in a continuous shot with her butt. It is not a really clear look at her face, but I am pretty certain it is her. I will update if I hear differently.