I just purchased one from Amazon. I makes fairly small circles, so far, my best results are with zigzag stitch. Kind of cool, you drop the feed dogs and the tool rotates the fabric sandwich backwards. First time I used it, I stopped and reread the direction sheet to make sure I wasn't doing something wrong.
I'm going to use it to quilt and decorate mug rugs and coasters. I think you could make some very interesting applique items as well. It wasn't quite what I thought when I bought it, but it's still better than a thumbtack and cork!