An alternative to developing new technology is to apply existing technology in a new way. I was thinking about face recognition software a few days ago, and thought of a fun application (this isn't a serious project at all, by the way).
So I quickly wrote AutoShoop, that uses a face-detection algorithm to draw "shoop da woop" shapes on people's faces. In other words, it automatically turns this:
This works automatically - no Photoshop needed!
I could have spent some time making the results better, but that's not really the point. It's more of a proof of concept.
I didn't write any of the face-detection part; I simply used fdlib.
Your results may vary; I found that for some reason fdlib sometimes has a hard time finding faces in certain photos. When it works, though, it works pretty well.