The fact that Wikipedia has unlimited space available for articles makes for excellent encyclopedia-browsing. Among the examples are the much talked about article on the heavy metal umlaut, the listing of fictional words used in "The Simpsons".
Todays find in this category is this article on fictional encyclopedia articles. Lengthy, interesting and fun.

While browsing away from this article I also discovered (which I hadn't taken notice of) that Wikipedia actually has an alphabetical index of articles, which makes that wonderful pastime of reading the article next to the one you need possible. It's just that Wikipedia doesn't include a link to the index from every page. I sense a bookmarklet coming on...