Google launched Hangouts for devices with Android 2.3+ that have a front facing camera (support for IOS is on the way). The new app is in the Android Market, now you can have hangouts at any time from anywhere.
Setup is pretty simple, you just need to start a hangout as usual and once on-the-air other people can join the room by pressing the “join hangout” button.
Google also has been working on some extras, such as:
Screensharing: for when you want to show off your vacation photos, your high score, your lesson plan or whatever else is on your screen
Sketchpad: for when you want to draw, doodle, or just scribble together
Google Docs: for when you want to write, plan or present something with others
Named Hangouts: for when you want to join or create a public hangout about a certain topic (like fashion or music or sports…)