Robin Good: Co-meeting is a real-time text-based group discussion tool. 

The key features of Co-meeting are:

1) Live-Typing Chat
Your text entry will be shown on screen character by character to the participants, so a text-based communication just like an actual verbal conversation is possible.

2) Multi-Threaded Discussion
Not only can multiple discussions be held concurrently, it is also possible for participants who join in midway and absentees to have the same level of discussion as participants.

3) Notes of real-time share
By simultaneously debating and sharing the minutes of the proceedings and preliminary information, additional work for information sharing is dramatically reduced.

From Lifehacker: "Remember Google Wave?

...Co-Meeting is a new web service that brings a lot of them back, including real-time, as-you're-typing conversations, document storage, in-line to-dos, notes, and meeting minutes, and more.

Co-Meeting borrows a lot of tricks from Google Wave, most notably the ability to have up to 30 people in one workspace at the same time, all typing and interacting with one another, updating documents, starting and answering comments and posts and threads, and in general just working together.

As everyone talks, one click turns any posted comment into a to-do item or a progress update to an existing to-do.

...The service even keeps track of where you left a conversation so you can get up to speed quickly when you return."

Full review: 

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