Chatzy is a neat little website that I learned about from Wes Fryer this morning. Chatzy provides a free platform for hosting your private chat area. To use it, simply name your chat area, select your privacy settings (you can password protect it), then send out invitations. Instead of sending out invitations you could just post the link to your chat area.
Applications for Education
Chatzy is a nice alternative to Tiny Chat because you can restrict access to it. Chatzy could be used to hold an after-school tutorial session, host a discussion about a book, or use it as a back-channel during a lecture.