Skype released a beta today of Skypecast, VoIP software that lets you conduct a live moderated conversation with up to 100 of your closest friends. It's a free preview, where you, as god of the Skypecast, get to control when people talk, and you can even eject obnoxious participants if you wish. Skypecasts can be held in two modes—open discussion, or one-way broadcast where you can open it up to questions and answers afterwards.
Unlike Skype's 10-way conference calling, which only works with Intel Core Duo chips, this is completely free of any such encumbrances. However, all Skypecasts will be publicly listed on the Skype website.
Product page [Skype]