You may already know about Yahoo Buzz, and now Google is going to release Google Buzz, a new social networking feature of Google, which will be integrated into Gmail and available for mobile phone.
One thing attracts me is that Google Buzz will automatically follow 40 people for you. These 40 people will be ones that you contacted most frequently.
For more information, you can visit the Google Buzz official page: Google Buzz.
And this is a introduction of Google Buzz from Google official blog: Introducing Google Buzz.
The following two videos are from Google blog to introduce Google Buzz and how it works on mobile phones.