I’ve just noticed that now you can search blogs using google at http://blogsearch.google.com/. Having this kind of search engine means that you can search blogs for specific terms with ease.
Still in Beta, the Google Blog Search isn’t only limited to blogger.com users, but it also covers other blogs too. Utilizing the Google Search, the site is certainly useful if you want to know about particular thing that people have blogged about.
Refer here for more information about Google Blog Search.