We use it for shared notes in our weekly status conference call. Status was great as you could see team members tweaking descriptions of subproject status where they shared work, etc. A lot faster than seeing the notes later or interrupting for something not worth stopping the speaker to correct.

On the fun side, with another group we use it extensively for D&D discussions where we need in-line comments/party-voting, etc. We take live quest notes together and there's all sorts of data being captured there that would be lost or post-merged later.

As Google has implemented the existing Wave, it's a great multi-person brainstorming and note tool. I really do love it for those and haven't found any alternative that works quite as well... we tried it out on a lark and it just became too useful and natural for all sorts of shared tasks.