Project Oxford is a fascinating and very entertaining application developed by Microsoft. You can load photos of people in it and the program will read the emotions displayed on the faces. There are eight emotions and the results give their relative weights.
You can upload your friends, family, celebrities, or favorite TV and movie characters.
Here's how it reads Miss Cellania's face:
The program is quite versatile. It's capable of reading non-photographic faces. Oddly, though, when I uploaded Sallman's famous painting Head of Christ, it said there was no face present.