In an attempt that I dramatized here, I dropped in on the weekly Plazes Product Forum in Berlin this morning via Skype videochat. While it was a great idea in theory, the technical side of the operation was such that while the audio was sufficient to get a sense of the room, the audio was muffled to the point where everyone sounded like they had socks in their mouths.
This is understandable, as the setup was simply a PC with a camera and a standard computer mic in a room with smooth echo-inducing walls.
iChat — which I think would have had better echo-cancellation — didn’t work on the spur of the moment because of firewall issues; the Skype connection was dead simple to set up.
So I seem the advice of the readership as to best practices for low-cost, Mac-friendly, higher-quality IP video-conferencing, with a focus on maximizing audio quality in a small room with up to 10 people gathered around a table.