I just read about a new company called Affectiva, which "grew out of collaborative research at the MIT Media Lab to help people better measure and communicate emotion."
This blog has previously discussed how human behaviour and sentiment is being analysed using data from the web:
(i) Web search volume can can improve forecasts of the current level of activity for a number of different economic time series, including automobile sales, home sales, retail sales, and travel behaviour (Google research paper on "predicting the present").
(ii) What people are searching for today can be predictive of what they will do in the near future (Yahoo! PNAS paper)
(iii) There have been various initiatives to make sense of sentiment data from Twitter
(iv) Facebook are analysing a rich seam of social networking and affect data
(v) Dan Hopkins and Gary King have developed an automated program to gather sentiment from online blogs
What makes Affectiva different to all of the above, is that (through their project Affdex), they have provided a way to collect web-data on physically expressed human emotions, not stated mood or revealed (search) preferences. Data on facial expressions and gestures — while people interact naturally with media, or other online experience — can be collected using Affdex. One could argue that this is closer to the objective truth than self-reported affect or observed behaviour.
Also, Affectiva's Q Sensor project measures galvanic skin response using a wearable, wireless biosensor. The sensor also measures temperature and activity.