Last week Beth Still recommended to me that I check out HootCourse. Beth teaches online courses for high school students so I knew that if she liked it, I had to give it a serious look. HootCourse uses Twitter, Facebook, Blogger, WordPress, Posterous, and Xanga to create a conversation channel for your courses.
At its most basic HootCourse is a platform on which you can create a conversation channel which HootCourse calls "courses". Your students can post comments and questions in the course you create. If your students have Twitter or Facebook accounts they can login using those accounts to post messages. Students can also post messages in Twitter, use the hashtag you assign to your course, and then HootCourse will pull all of their Tweets into your course. If students need to write more than 140 characters they have their posts on Blogger, WordPress, Posterous, or Xanga appear in your HootCourse course.
Update: apparently if you login into HootCourse using your Twitter account and make your course public, all of your messages appear in HootCourse as well as on Twitter.
Applications for Education
HootCourse categorizes students' messages into comments, questions, and links. Anytime a student uses a question mark in a message, that message will appear in a column just for questions. If you're using HootCourse as a backchannel during a presentation the questions column will make it easy to find the questions your audience is asking.
Last winter I used a backchannel during a classroom viewing of the movie Glory. In the backchannel I had students asking questions as well as posting comments. HootCourse would have made it easier for me to address my students' questions in a timely manner.
By providing your course with a category for messages containing links, HootCourse could be useful for sharing of links that are relevant to your course discussions.
Here are some related items that may be of interest to you:
Neat Chat - Quickly Create an Ad-Free Chatroom
Five Platforms for Classroom Back-channel Chat
Back-channeling During a Class Viewing of Glory