I'm currently a bit obsessed with the Face of Tomorrow project. Around a hundred photos of people from each city are layered transparently over each other to form a facial composite archetype for that city. The artist who started the project was interested to see what a multi-ethnic person would look like, one formed from the people he encountered in each city.
The results look slightly stylised but still quite realistic. I'm not sure how the technique works, but to me it look like each face has been slightly elongated or otherwise manipulated to match up the location of the eyes, nose and mouth.
The Sydney composites archetypes are kind of spooky, these people don't actually exist yet they really do look like any number of good looking, slightly Mediterranean faces you might see on the streets of Sydney. The archetypes formed from pictures taken at Bondi Beach and Sydney University are quite unique to each location.
My only one quibble is the youthful good looks of most of the participants. The brief says that they approach 100 indidividuals, but it seems that the locations like beaches and universities (in Sydney at least) are designed for a young and attractive demographic. Having said that, I guess the archetype works best though if you have people of various ethnicities but a similar age range. It would be nice to see the same exercise with aged people, for instance.