#Happy? #Sad? Twitter Selfies May Reveal Our Moods

To see how happy city dwellers are, it may help to look at the photos they post on Twitter, according to researchers who recently won one of Twitter's first #DataGrants.

By analyzing 1 million photos tweeted over a period of one year, researchers are planning to measure the "moods" of some American cities. The team, including researchers at the University of California, San Diego, and the City University of New York, will correlate the Twitter image data with other sources of happiness data, such as the Gallup Poll results.

The project is one of the six winners of the Twitter #DataGrants program, which gives researchers access to Twitter datasets. One of the project's highlights will be an analysis of selfies that people post on Twitter, to see whether, for instance, people who live in "happier" cities tend to post more selfies, and whether they smile more while taking self-portraits. [10 Technologies That Will Transform Your Life]