Google+ hangouts allow you to have a video chat with up to 10 people at the same time.
"Anyone in the hangout can invite anyone else."
"While you can invite as many people as you want to join a hangout, you can't have more than 10 people in a hangout at once. If additional people try to enter, they'll be told the hangout is currently full."
Hangouts require a one-time free download of "Google voice and video chat."