Here's a site I recently built for fun: the Web 2.0 Name Generator. I got the idea for it after reading TechCrunch for a while, and being amused at all of the silly company names people are using these days. I guess that's a hallmark of a Web 2.0 company: silly name. (Admittedly there's a practical reason for having a nonsense name: domain names based on real words are almost always already taken. Your chances of getting a .com name are a lot better if you just make up a word.)