MeBeam.com, K-12

http://www.mebeam.com/
MeBeam is a free chat room platform with built-in audio and video capabilities. This means users can get a real time group conversation going with friends around the world—it would be just like being in the same room at the same time. To start a chat, type in a title for your room or find an existing chat to join. From there, make sure your webcam is adjusted properly and test your microphone. Once that’s all in place, invite friends by pressing the Invite People button. Up to 18 people may join in on the conversation. Users may upload files for others in the room to share.