Having students write Wikipedia articles

Fabulous example of using real world writing as a class assignment:

Have Students Build Articles
In the Spring of 2008, Professor Jon Beasley-Murray at University of British Columbia had the students in his class "Murder, Madness, and Mayhem: Latin American Literature in Translation" create articles for Wikipedia on the books that they read. He transformed his students from learners to teachers, which improves outcomes. Plus, creating public work improves motivation as well as performance.
Importantly, the students were instructed to make contact with the Wikipedia editors—called the “FA Team”—to receive feedback on their work for revisions. The instructor had effectively enlisted outside academics as reviewers for his class. Wikipedia also has a quality ranking system that assigns “Good Article” or “Featured Article” status to exceptionally good works. About 1 in 800 articles reach Good Article status, while 1 in 1,200 reach Featured Article status. The instructor guaranteed his students an “A” for Good Articles, and an A+ for Featured Articles.
The results? The students, who worked in groups of two or three, produced three Featured Articles and eight Good Articles, an exceptional result given how few articles achieve these levels. These articles receive thousands of hits per month, demonstrating to students the value of their work. Now more than 20 universities have projects in Wikipedia.

From Faculty Focus.