Wikirandom is a website that (naturally) grabs random wikipedia articles. The obvious question is so what?
I'll tell you what: interface. It's all ajaxy and cool, and it even lets you embed a random-wiki-article-getting widget in an external site. That looks like this:
Some random Wikipedia articles:
More randomness on Wikirandom - The Random Encyclopedia
(Edit: hm. That doesn't work, does it? Blogger strips line breaks; it might be that.)