Google wave is a new communication and sharing tool coming this year. With wave people can do lots of this things in a single browser like communication,videos,map link sharing, rich formatted text etc.
You can have a group chat and any participant can reply anywhere in message. edit content and add participant at any point any time.
You can also do lots of things like created gadgets thanks to wave api available on wave.Google.com.wave.Google.com is having key technologies like natural language processing, Real time conversation etc. Here is the some video for that.
Natural Language Processing:
Another one live collaborative editing.
If you want to play with wave google api then here is the link for that.
And here is the Google developer preview video.