If you are like me, you probably find yourself with two or more pictures of people --- taken during a short period of time --- where the smiles or frowns of one or more people in a picture are not good. Here is an example of two shots (see below) that were unsatisfactory.

Enter CS 3 for a quick fix!! I loaded both images into one file, selected both, and performed – EDIT / AUTO ALIGN. That adjusts the top layer to match as well as possible the bottom layer. Then selecting the top layer, create a white layer mask, and then use a soft black brush to remove the face that needs to be fixed.

This is a wonderful feature in CS3. Try it!