Whilst recently training to be a ICT peer coach and facilitator I was introduced to TitanPad http://titanpad.com On the course we used TitanPad in an activity. To being with we were put in gropus of 5, we then had to decide on a group name, we originally picked group 5. 1 person in the group had to go to http://titanpad.com/group5 to create our pad. Once it was created the other members of the group could go to http://titanpad.com/group5 and join the pad.
Once the pad was set up we individually read an article than in separate places around the room with our laptops had a discussion about what we had learnt from the article and the important factors covered. The whole room was silent (apart from numerous giggles and the busy tapping of keys) but fantastic discussions were taking place. Each persons comments showed up in a different colour so it was easy to see who was contributing what point. You could go back up and recap the discussion and add your opinion below the points discussed.
From a teacher point of view it would be an excellent discussion tool for a group of students as students could have the time they need to reflect and think about what they want to say, shy or quieter students may be more confident contributing to the discussion, teachers can see what students are contributing and maybe add a question to keep groups on task, there is a watch back tool which shows the comments happening in real time which could be a good assessment too. You could get students to log on as student 1, 2 etc so comments are anonymous making it safe for students to contribute to the discussion. It could also stop one student taking charge and doing all the work - all students would be accountable for their own work.
I really enjoyed using the tool and found we discussed alot more than we would have done face to face where we might have broke off into smaller groups and had side conversations or got completely side tracked.
I can't wait to use this is my classroom :)