An old one, but still good for giggle! please log in to view this image Followed by some rather miffed goons....which is always nice! please log in to view this image
You'd need to start with doing some photoshop stills first, because there's terms that would mean nothing to you otherwise. I use a free one I found on the net. You start with a picture, then just add the faces you want by using 'layers' over the top. Use another picture of a face you want, if you use google images you can choose the right size pic. Then you use an 'eraser' tool to basically rubout the rest of the pic leaving just the face, then move it in to position. With moving gifs its similar, but with multiple face expessions for how many frames of movement. I could probably talk you through a 'still' easy enough, but not a gif....there I again I might just keep my secrets to myself!