Google Buzz is the latest social-networking site, a combination of Twitter and Facebook, and of course many other things.
The first idea that occurred to me was the name: Buzz. Google has its way with names: Chrome, Wave, and now, Buzz. I thought the name was strange. You tweet on Twitter, so I presume you would buzz on Buzz.
It is by default integrated with Gmail, so it took little effort to begin using it. Seems pretty nice. It feels for the most part like Twitter, i.e. you can follow people without their following you back, and you post messages. You can comment and like messages, as in Facebook. You can also edit your own status messages and replies, email messages to others, and reply to messages by chat. In fact, they are not so much statuses as simply what you are saying; your current message is not highlighted at the top as they are in Facebook and Twitter. Buzz also has the concept of connected sites, which are basically integrations of other sites with Buzz. This means you can allow tweets for example to automatically show up in your Buzz stream, or even full length WordPress blog posts.