Apologies for the cross-posting!
I gave an interesting assignment last semester that asked students to complete their research paper as an article on Wikipedia. My course was recently profiled on the Wikimedia Foundation blog.
http://blog.wikimedia.org/2012/01/04/design-professor-gives-students-real-world-experiences-through-wikipedia-assignment/
Of particular note, the article covers my reflections on the way working on Wikipedia changes students relationship to power, forces/inspires them to do real research, inspires them to work for the greater good, and curtails/moderates plagiarism.
I will be trying a shorter version of the assignment with the Core 2 seminar in the Interactive Technology and Pedagogy Certificate Program at the Grad Center. More on that as it develops.
Michael