Feel-o-meter.

A posting from Poetry Café

True “urban poetry”! The Feel-o-meter is an interactive art installation that calibrates the mood of the city in which it has been erected with a monumental illuminated Smiley. The project is about a smiley on a huge screen from which one can read the average mood of the inhabtitants of a city.
The system allows to read emotions out of random peoples faces. The faces are analyzed by sophisticated software (contributed by the Fraunhofer Institut). The obtained mood data are then stored on a server and processed by the smiley on the screen to visualize the emotions in real-time.

Link
Feel-o-meter Website