Riccardo Raneri demonstrates how to use a free tool from Microsoft, Group Photo Fixer. To use it for your next group photo, take several shots of the group. That’s a good idea anyway–with digital cameras, pictures are free, but so many people still only take a single photo. After you load your pictures onto your computer, if you discover that no one photo has everyone smiling with their eyes open, you can swap a person’s face from another photo. Give it a shot.
Update: James O’ Neill provides another interesting use for this tool–removing moving objects from a still image, such as crowds or cars walking in front of what you want to shoot. I could have used that in Pompeii.