I'm going to be doing a series of free live phone calls with my subscribers to talk about various IM topics very soon and I need some brainstorming/advice for one piece of it.

Hundreds or more people will be listening in on each call, but I don't want "one-to-many" communication. I want the crowd interacting the whole time. I won't be using any video feed or webinars for these calls, but I would like to have the listeners be able to "chat" with each other and with my moderators while I present.

Anyone have ideas better than just using a facebook 'fan' page?

Any other ideas outside of the "go to meeting" type of set up? I'm not a huge fan of my experiences with that software so far.

Have you been on such calls before and had a great experience? What software was used?