I did like the idea of PJ of checking checkboxes in "Participants" list and having a button to send either instant message/e-mail to all checked. A similar checkbox could be added to the Groups lists. I see quite natural to use the "Participants/Group" lists as a king of adressbook from where to dispatch messages.
PJ had a working example, do yo see implementation / functional problems in this approach?
- Enrique -