I'm sure I had quite a different experience with the collaboration assignment as I wasn't able to make it to class. I found it interesting that I was still able to participate with out actually talking to the other students. It gave me some pretty good insight into the idea that if a student was going to be out of town, or was otherwise unable to attend school, if they had access to a computer with internet, they could still participate in classwork. Even in a class like mathematics, the teacher could have a technology day and run the notes/lesson through the computer and the absent student could ask questions, or work problems and be able to get feed back right away.
On a more text based idea, (like a Literature or Composition class) I would use a Google doc to allow students to work collaboratively on stories or something like that. I think the Google docs are great tools to allow students to learn from each other.