"How many people can conference call at once? Technically, there is no limit to the number of people that can conference call together on the Gizmo Project system.
We have found that as a practical limit, the sound quality degrades once you have more than 4 people.
You can get around this limitation by having people put thier Gizmo Project's on mute while they're not talking. Using this system of putting everyone on mute, we have had successfull conference calls with as many as 28 people in 11 countries."