"Group Shot" http://research.microsoft.com/projects/GroupShot/Compose your photo from many parts of others
A free Tool from the Microsoft Research Group.
A product of Microsoft Research’s Redmond lab, Group Shot was developed by Alex Colburn, Matt Uyttendaele, and Michael Cohen of the Interactive Visual Media group over a period of six weeks late in 2005. Group Shot has the express purpose of helping a user to improve a flawed group photo to the desired state envisioned when the picture was taken.
“Photographs are instants of time,” Colburn smiles, “but we don’t necessarily remember an instant in time. We’re actually remembering a moment, and our brains backfill in the details. For example, you don’t remember your family portrait as a moment when everyone has their eyes closed and their mouths open. You remember a moment when everyone is smiling and looks good. With a camera, it is hard to capture those perfect photos, because those moments might not have existed, or you may have just missed them.”
“What we want to do is to use multiple photos to help reconstruct a moment.”
Group Shot, available for download, makes it easy for a user to take a part of an image from one photo and replace a similar but flawed part of an image in another photo, thereby creating a composite shot better than either original and more approximating what was seen in the photographer’s mind’s eye.
Not tested yet by myself, but it sounds interesting as you not only can change persons. You can also clip out unwanted parts and/or take a photo with and one without flashlight and compose a new image from that two with any lightning level that looks best for you.
There are many more (mostly very weird) projects to download from the Microsoft Research Group under http://research.microsoft.com/research/downloads/default.aspx
Hope this post is useful to someone out there.