Google Wave looks pretty awesome.
Google Wave really looks like it could revolutionize web communications. I could definitely see this replacing email, IM, and other current web communication protocols. I will be keeping a close eye on this.
Google Wave is a product that helps users communicate and collaborate on the web. A “wave” is equal parts conversation and document, where users can almost instantly communicate and work together with richly formatted text, photos, videos, maps, and more. Google Wave is also a platform with a rich set of open APIs that allow developers to embed waves in other web services and to build extensions that work inside waves.
Here are some links for further reading.