Transparent half circle cut out of a div

Question

I would like to make a transparent cut out half circle shape using only CSS3. The only requirement is that all the elements that form the shape must

Answer 1

Kyle Sevenokas did some good work. And I built off of that. Checkout the http://jsfiddle.net/FcaVX/1/

I basically collapsed the white div for the circle and gave it white borders. The OP question talked about the colors elements that make up the shape; nothing about its borders right?