Here's how it works: In Google Wave you create a wave and add people to it. Everyone on your wave can use richly formatted text, photos, gadgets, and even feeds from other sources on the web. They can insert a reply or edit the wave directly. It's concurrent rich-text editing, where you see on your screen nearly instantly what your fellow collaborators are typing in your wave. That means Google Wave is just as well suited for quick messages as for persistent content — it allows for both collaboration and communication. You can also use "playback" to rewind the wave and see how it evolved.
Google Wave arrives on September 30th. On that day, Google (Google) will start sending out 100,000 invites to non-developers to its much-anticipated real-time communication platform.
It’s not even released and it’s generating more hype than almost any other web product in recent memory. The reason stems from its game-changing features and their potential applications on business, education, customer service, email, social networking, and more.
Google Wave Developer Preview presentation at the Day 2 Keynote of Google I/O