"MSR Group Shot helps you create a perfect group photo out a series of group photos. With Group Shot you can select your favorite parts in each shot of the series and Group Shot will automatically build a composite image."
Charles Arthur adds: I saw this last year at the open day at Microsoft Research in Cambridge (UK), where it was called Grabcut (link to the original MSR page). It looked very interesting - a weird variant on Orwell's 1984, where rather than banishing people to the memory hole, you'd put them in places they'd never been.
Of course, we saw something like this used for political ends in the last US election (Jane Fonda on a platform with John Kerry, anyone?)
