This is a composite of a recorded video of smartphone being held and the screen swiped three times to display four images. The background and screen are keyed out, and the screen has been motion tracked to allow images of your choosing to be placed on the screen.
Follow the steps in the text editor and you should end up with something like this:
https://www.youtube.com/watch?v=AgwaE9CmjsI
This Blend file was created by Hudson Barkley (aka Snu) and is licensed under a Creative Commons Attribution 4.0 International License (CC BY).
The phone in the video is a Motorola Atrix 4G, the hand is mine.
I used it for an announcement video for a church to show contact information (facebook, twitter, web). I could see it being used as a silence cell phones video, or as a commercial of some sort, or simply as an example of compositing to learn from.
So what is this useful for??