Chat in the stream
You can chat with anyone as long as you both have each other in Chat enabled Circles. To start chatting, type their name in the Send a message to... field and select it when it comes up. A chat window will open where you can send a chat message.
You can also make a computer-to-computer voice or video call by clicking the phone or video camera icon at the top of the chat window.
Your Chat list will only appear while you're in the stream.