Google+ (G+ for short) may not be the Facebook killer Google wanted it to be, but one of its handier auxiliary features is Hangouts. This group-conferencing function allows up to ten G+ users to chat in real time via camera, microphone or text.
Aside from a G+ account and a webcam/mike, you'll need either a browser plugin (available for just about all late-model browsers) or the G+ client app for phones or tablets. Those who don't have cameras can be invited to participate via phone, and everyone in the hangout can contribute via text chat. Note that text chats in Hangouts are not saved in your Gmail chat history for those contacts, so you'll have to log those conversations manually if you need them.
Setting up a Hangout is straightforward enough: go to https://plus.google.com/hangouts or click on the Hangouts button if you're already in Google+, log in if you haven't already, select "Start A Hangout" at top right, and choose people to hang out with from your G+ contact list. Up to nine people can take part in a Hangout.
The chat interface places everyone's talking heads in a row along the bottom, with the speaker taking up most of the display, and a text-chat panel at left. As with Skype, Hangouts switches the video feed so that whoever is speaking is given prominence. Also, as with Skype, a built-in screen sharing function lets you pick an active window on your desktop and share it with everyone in the hangout. (It's one-way sharing -- the others can look, but not change anything.)
Hangouts can be augmented with one of a slew of specialized apps -- essentially plugins for the chat experience, which run on the server side. For example, the YouTube app lets you play back a YouTube-hosted video for everyone in the chat (although Google strongly discourages rebroadcasting copyright content this way unless you own it). Plugins for Google Docs and the SlideShare presentation-hosting site allow documents hosted with those services to be browsed collectively, and in the case of Google Docs case, edited collaboratively as well.
Hangouts also has a number of interesting features of its own. For example, Hangouts On Air lets you record a hangout and re-use it, or broadcast it to any number of viewers. (This is an advantage over, say, Skype, which doesn't have its own recording feature.) Note that you can't use Hangouts On Air to rebroadcast a pre-recorded YouTube video.
Another useful function called Ringback can be used to reconvene a hangout if attendees missed it. And if you're feeling slightly silly, Google Effects uses face recognition and motion tracking to let you overlay goofy accessories like hats or mustaches onto peoples' faces.
If you and your associates have Google+ accounts, this is a fine way to do group video. The external add-ons have real value as well.