Sticking photos to moving 2d images

http://www.facehumor.com/Create-FaceHumor/773.html is an example of what I need to do, however the image needs to be moving, and the users uploaded photo with it!

Does it have anything to do with creating a mesh to stick the photo onto?

If some one could tell me what this process is called, so I can google some tutorials, or if they have some links for me … PLEASE!! Reply.

Thanks,
Katie.8-]