Currently, there is widespread interest in how Web 2.0 tools can be used to improve students' learning experiences. Previous studies have focused either on the advantages of wikis or on concerns over the use of Wikipedia. In this study, we propose to use Wikipedia as a classroom wiki. In doing so, we discuss how students can improve their standard written assignments using Wikipedia instead of a module wiki. Compared to traditional essay assignments, students' submission of articles to Wikipedia can address many of the problems faced by instructors of traditional assignments, such as students' poor writing skills, lack of primary source research, and poorly balanced discussions. Our study was based on our experience in teaching an upper-level economics module at the National University of Singapore over two semesters: 121 students who were enrolled in semester 1 submitted a traditional writing assignment, while 124 students enrolled in semester 2 contributed two short entries to Wikipedia. The results showed a large increase in the number of students checking their assignment feedback. Further, students' writing quality improved noticeably in the Wikipedia assignment, and they were able to put forth more balanced discussions of relevant issues and include a greater number of primary sources. Despite the challenges faced when using Wiki markup language, the students enjoyed the overall experience.