Max Klein:

But in general, if you are collaborating with people and you have not tried Google Wave, then you are perhaps missing the greatest thing to happen to small web based businesses since Dropbox.

This may be the only instance where I have heard of someone actually using Wave in a productive manner. I thought from day one that Google was in trouble for the simple reason: I knew no one on Wave. Klein should check out Basecamp and Campfire though, they may fill the role nicely.