Robin Good: ooVoo has just released a new Facebook app allowing any user to videoconference at zero cost with up to 12 people.
No registration or download is required.
ooVoo is a downloadable software available for Mac/PC/Android/iOS.
More info about ooVoo: http://www.oovoo.com
Try it: https://apps.facebook.com/ooVoovideochat/
(Thanks to Jaana Nyström for discovering this one)
Via Robin Good