Google Buzz is a social network service
Google Buzz tries to keep Google up to the world that's addicted to Twitter and Facebook. Gmail users can post messages, track updates, and respond with Google Buzz. You can share texts, but also videos and photos (without the need for external services). Updates can also be automatically imported and shared with the world, or with a limited number of people. Because Buzz lets you know where you are, it tries to bring the offline and the online world into contact with each other.