If you remain unconvinced, please take a look at the result of this group collaboration by distance at Bloomsburg University of Pennsylvania's Department of Instructional Technology. The fruits of their group collaboration have been posted for everyone to view and they may be of interest to you if you are reading this posting. They've created an e-Book entitled E-Learning Concepts and Techniques. It has 11 chapters and has some tidbits in there that are an interesting read.
Are you interested in seeing the actual assignment instructions that the students received? I was! And I was pleasantly surprised that the instructor(s) posted a link to the assignment for all of us to examine.
To me the strength of the assignment was that students had some choice as to which part of the e-book to contribute to. This allows students to gravitate towards an area of personal interest. This strategy often increases the relevance of the assignment to the student and thereby increases the intrinsic motivation of the student. Experienced distance instructors quickly recognize that motivation is the 'golden fleece' in distance education! One nice feature of the assignment is that it points the students in the direction of some collaborative work tools (i.e. Skype, Gizmo and GoogleTalk) as well as some software tools (i.e. Audacity and GarageBand for audio) that might facilitate the completion of the project.