One of the biggest complaints from first time Google Wave users is the tidal wave of information and updates that threatens to suck their precious time away as they watch the chaos unfold.
In a carefully tended wave, the noise and chaos are minimal, but in some of the larger (public) waves, users have given up hop of ever keeping on top of it all.
Charles Lehner has created a simple chat gadget that might help calm the swell, by focussing some of the chat into a form most of us will recognise: IM. By introducing this gadget to a wave, you can give people an outlet to speak that brings in years of built up convention for managing the flow. People understand Instant Messaging, so you can add this gadget to bring normalcy to the new medium.
Perhaps you could embed this in a wave and encourage people to use it for idle chitchat, leaving the rest of the wave for the real-time collaboration on the task at hand.
As with other gadgets the Playback function records every new person who gets to the chat, and every message, so be aware that this can blow the size of your wave recording out with a lot of extra updates to wade through if necessary.