Etherpad is a web-based word processor that allows users to edit the same document simultaneously. Unlike Google Docs, Etherpad updates instantaneously, allowing real-time collaborative text editing. I recently used Etherpad for an in-class brainstorming activity for essay topics.
We all logged on to the same document and started listing possible essay topics. We were all typing furiously without worrying about whether the topic was good or bad, just getting our ideas into the document. In five minutes we had generated about 250 possible topics. We then looked at the document as a class, picked out a few topics at random, and discussed the potential of each topic, how we might refine or broaden the topic. After class, I exported the document to a PDF file and uploaded it to Blackboard. Students were then able to use it for ideas as they wrote their project proposals over the weekend.
One drawback of the program is that only 13 users can be logged on at the same time. It would be ideal for all 22 students to be logged on at the same time, but I simply had some students buddy up and write together.