An interesting article on Wikipedia in the New York Times Review of Books by Nicholson Baker. I don’t contribute to Wikipedia at all, but I use it regularly and see it as a continual dialogue on contentious issues.

Baker says that Wikipedia is an incredible thing. It's fact-encirclingly huge, and it's idiosyncratic, careful, messy, funny, shocking, and full of simmering controversies—and it's free, and it's fast. This gigantic encyclopedia isn't a commercial product. It was constructed, in less than eight years, by strangers who disagreed about all kinds of things but who were drawn to a shared, not-for-profit purpose.

Baker adds that:

Without the kooks and the insulters and the spray-can taggers, Wikipedia would just be the most useful encyclopedia ever made. Instead it's a fast-paced game of paintball.Not only does Wikipedia need its vandals—up to a point—the vandals need an orderly Wikipedia, too. Without order, their culture-jamming lacks a context. If Wikipedia were rendered entirely chaotic and obscene, there would be no joy in, for example, replacing some of the article on Archimedes with [nonsense]