Wikipedia, founded in 2001, is a free, collaborative, online encyclopedia. Anyone can edit any article, or add new articles. This might not sound like a great idea, but things are monitored and uncited facts are removed and dubious articles are clearly marked for revision. The system allows for the encyclopedia to grow constantly and to reflect not just information typically included in an encyclopedia, on historical and scholarly subjects. Wikipedia offers information on the most current topics in art, science, music, geography, news, politics, and anything else I’ve ever searched for. It’s easy to attack the site for being unreliable, but it is well monitored and undeniable useful.
As an artist, I find Wikipedia a fantastic subject to work with. I appreciate the site for what it is and working with it I have an excuse to peruse all sorts of information. When working with network visualization Wikipedia is very easy to glean data from. All pages are standardized and even include convenient HTML comments marking off sections of each page. Although this also makes it a very poor analog for the world wide web, which is far from standardized, it is a great starting place and simplifies a lot of tasks. In addition, since the entire site is under an open content license the data is free to use.
My most recent project WikiWeb is a live, interactive, visualization of the site. Another limb of this project will hopefully lead to a static map of the whole site. A few other small visualizations are on their way as well.