You have heard it many times! Very often, I had to produce samples of what UI will look like to start the conversation with users. Too often I have created forms in a dummy application just for the sake of getting an image to show to the user. When the image satisfies him, he thinks that most of the job is done and everything will be ready for the next day. Sounds familiar to you too?
We always had other tools to “draw” samples UI. Blend comes SketchFlow but not everyone has it.
If you have Visual Studio 2012 Premium or Ultimate (and PowerPoint 2007 or better), you now have another tool. After you installed VS2012, you will find “PowerPoint Storyboarding” under your Microsoft Visual Studio 2012 menu item.
Devon Musgrave wrote a nice little introduction on how to use it at http://blogs.msdn.com/b/microsoft_press/archive/2012/09/10/from-the-mvps-visual-studio-2012-meets-powerpoint.aspx.