For mining the blogosphere, the options expand. There are dozens of blog-specific search engines (you can find a good list at aripaparo.com/archive/00632.html), but the most popular ones are Technorati, Google Blog Search, IceRocket, Blogdigger, Blogpulse, and Bloglines. Zuula is a new meta search engine that just does blog search. There’s even Twittersearch, Terraminds, and Twittermeter, which search only Twitter messages.