I have been using ManyEyes for a few years, one at Surrey we used a couple of years ago was a mini-project to compare market data and market news to explore relationships.
From what I remember, gathering the news was mostly a cut and paste job and a 100+ page doc of multiple blogs, comments, online newspaper articles.
Some examples of the original mindmap before we started, the blog text (very waffly) and a topic center on Many Eyes.
Also a Density Design presentation on visualization and design.