I tried a Google Hangout a few weeks ago.
It was pretty straight forward, has up front options on public or private room.
Once you have people connected, its really quite fun. People with cameras show up in a film strip fashion at the bottom of your screen, those without have their Google Icon as their avatar. When someone talks, Hangouts automatically focuses on the speaker. Though you can manually jump between people as you want. You can join a hangout without a camera and mic and just go straight text.
One of the coolest features is the apps section which allows you to use YouTube to play videos. You can lock the playlist down to only one person adding videos to, or allow anyone to do so. If you wanted to create a workshop and you have a video you want to show, it can be done quite easily.
I would highly suggest playing around with it with a few people to understand the subtle nuances of the software, but I feel, as a whole, it is a great free collaboration tool.