When I was invited to a 90-minute brainstorming conference call for a not-for-profit organization I belong to, I confess I dreaded the meeting.
So of course it was a very productive session. Here's what I learned:
 Brief introductions are helpful so that we can all know the other voices who are speaking. In this case, there were 12 on the call, many of whom I knew already, but not all.
 Set up ground rules. Among the ground rules were to start with creative stems like "How could we" or "I wish we could," instead of rambling, apologetic time wasters like, "Well, this might not really be a very good idea..."
Another ground rule, mostly honored by breaking it, is to let other people know when you are finished speaking by saying "Done," so others can jump in.
 Get people off to the right start with a simple exercise to get them talking. In this case, Laurie asked us about creative fundraising approaches we had seen in other parts of our lives. There's really no wrong answer to a question like this, and it is so much better than saying, "Okay, who has an idea to share?"
 As the facilitator, acknowledge those using the right approach, provide lots of encouragement, and change the topic when the ideas start to dry up. (All things one does in face-to-face facilitation, of course.)
 Before the meeting, send out some helpful tips, and a 10 minute simple advance exercise. This was tremendously helpful, actually, as I knew what to expect, and had also mentally started brainstorming on the topic even before we started.
I personally would have liked having a shared screen showing all the ideas being typed up. Or having a chat window to use to add all the things rushing around in your head in between getting to talk. (But that may just be me... I have idea traffic jams pretty regularly.)
Think how much more productive your own office meetings and conference calls would be if a little active facilitation skill was used? This point was beautifully made by Marc Solby in his article Facilitation First Aid.
What are your telephone brainstorming tips?