PMware vs. Wave
I've grown skeptical of most new collaborative communication tools. They always seem to suffer from an inherent problem: they feel like they were designed by project managers for project managers. (When I worked at Microsoft, I called this PMware. Microsoft is basically packed with PMware.) This use-case is, needles to say, quite limited. But I can see Google Wave spreading to a larger audience. The demo is 80 minutes long but O'Reilly has a summary. It essentially collapses IM and email into a wiki-like space. It's pretty cool.