Wikipedia defines back channeling as "the practice of using networked computers to maintain a real-time online conversation alongside live spoken remarks."
In a nutshell, the teacher is presenting information and the audience is fully engaged by listening AND typing notes and questions back & forth to one another. I know...it sounds crazy, but it works. Rather than just being passive listeners, students have to be fully engaged in the discussion taking place.
TodaysMeet is a free service that lets people set up private chatrooms. Set-up takes less than 30 seconds and students can be logged in and back channeling within a minute.
Notice there's even a way to integrate
Twitter by using hashtags. Why would this be useful? Lets say you give your students a homework assignment to watch the State of the Union speech and back channel their questions & comments throughout. If you were to put the hashtag #sotu anyone on Twitter would have their comments automatically posted to your chatroom without them even knowing it. This might be helpful to give your students a different perspective on what they're watching.
Just provide your students with the website address, have they type in their name, and you're off & running.
Below are a couple good posts regarding back channeling in a classroom. It would also be useful for homeschooling networks to facilitate online live discussions about things just like the State of the Union speech.
