I imagine that Wiki’s are the inspiration for this new medium. Google’s Wave is equal parts conversation and document. Using rich text, photos, videos, maps and more, people can communicate and work together in a new way.
“Any participant can reply anywhere in the message, edit the content and add participants at any point in the process. Then playback lets anyone rewind the wave to see who said what and when.”
Google Wave Features
— lets all people on a wave edit rich media at the same time.
Server-based models provide contextual suggestions and spelling correction.
Waves may be embedded in sites or live social gadgets.
(read more here: http://wave.google.com/help/wave/about.html)ch