Dave Campbell's WPF/E Reflection Editor
Dave has put up a new WPF/E sample he built for a recent INETA talk. The sample has two images and sliders to manipulate their position and transforms. This enables you to build some nice 3D-esque reflection effects like the one I built below. Dave's blog post also has the source for the sample.
Note that the sontrols for editing are disabled in the image below. To see the controls, just toggle the third checkbox in the sample.