In my last post, I pointed to Wikipedia as a potential example for citizen-centered media. If you are unfamiliar with Wikipedia, it isn't immediately clear what it is good for. I compiled a brief overview on my personal Wiki, where it will be updated as more information becomes available.
To summarize, Wikipedia is good for topics where there is no controversy, no expert, or you just need an introduction to a topic and are looking for references to more reliable articles. The Wikipedia administrators are working on ways to make it more reliable, and I look forward to future improvements.
For what it's worth, the Guardian recently published another article about Wikipedia.