To create a double-sided panel that can be turned around is quite common. Most of the designwork you will find out there has one major lack of user experience, which is the turn around transition that happens when the user swivels from the frontside to the backside and vice versa.
So, I thought this could be done much smoother and more natural. I ended up in a double-sided panel with a quite nice and smooth transition. The panel is not a user control or a custom control, but a simple Grid control. However, the panel itself is not the focus of the sample I built, but the transition which I created in order to swivel the panel. The panel does not simply swivel around on an imaginary Y-axis, but it withdraws and shrinks a little bit during the process of turning and then let the other side appear. As a result, you get a very nice, fluent and natural swivel effect.
You can grab the source code and view a sample app at the Expression Gallery.
Have fun!