thanks for your last para (especially ;)) Bronwym- there's alist of sl-mod comps there.
Great sl-tivities too!
Another useful aspect that I have found in SL sessions is that most facilitators have the audio pre-recorded and then use the text chat to either take the attendees through the transcript (useful for those who aren't voice-enabled) or use the IM to deal with individual queries or technological problems. Having the backup of text-chat is helpful.
As Bronwyn has said that moderation/facilitation in virtual worlds requires more planning than other environments: the timing, using multiple media, using more than one channel for communication, communicating to individuals and to the group, and keeping up the maximum use of the 'social context' and 'physical presence' through activities, objects, music, and so on.