This appeared this morning.
Festoon looks like a product that has a chance to catch on. It seems simple, straightforward to use, apparently supports multiparty audio/video (and one to many with up to 200 viewers), and has an application and desktop sharing feature. It will piggyback on the Skype or GoogleTalk calling and presence functions. I really haven't seen it in action and don't know whether it is practical (especially from a bandwidth usage point of view) but seems to offer everything that I long ago wished NetMeeting had.
It seems to have a shortcoming that was also obvious in NetMeeting though (though there at least a pull through of other Microsoft product purchase was potentially possible)-- there seems to be no obvious way to make money.
