David Anson has created a short video demonstrating how a Silverlight-based Windows Phone application behaves when you rotate the device. You can also download the code and use it in your WP7 apps.
I wanted to make it easy for developers to animate the orientation change of an application that occurs when the phone is rotated from its default portrait orientation to landscape. This is one of those cases where a picture is worth a thousand words, so I've created a short video showing the default behavior of a Silverlight-based Windows Phone application when the device (in this case the emulator) is rotated.