There is a nice API for face/person recognition on the internet at http://www.face.com/.
Their API provides quite a lot of interesting data, such as
- Position of the eyes
- Position of the nose
- Position of the mouth (right, center, left bounds)
- Yaw/roll/pitch rotation of the detected head
- Attributes: gender, wearing glasses, smiling, mood, …
And the best of all … it’s a free service which gives you 5000 calls an hour to their API which is more than enough for a little experiment.