It's a "Pop Out" card and I found a very easy to follow tutorial on the Craftwork Cards blog, written by a crafter named Hazel.
Here are a few other views of the card:
For my inside sentiment/image, I used this great set from DigiStamp Boutique: Flower and heart circles. I wanted something soft and round with all of those sharp angles. My papers are an assortment of SU! (green), Creative Memories (pink floral/swirl) and Penny Lane by My Minds Eye (stripe).
The finished card is pretty large (6" square) and pretty bulky, so this isn't a card I can see myself making very often. But Hazel's tutorial was easy to follow and it was a lot of fun to make, so I'm sure I'll be making another one in the future.