RSS Directory, from blogStreet, “contains a listing of 11,000+ RSS feeds of blogs, making it one of the largest directories of RSS. An added advantage is that the latest feeds of the listed blogs can be read through RSS Discovery – RSS Discovery finds out the RSS feed of a blog, the time when it last changed and displays the latest feed in HTML.” Find a blog using the search engine or the alphabetical listing.
See also Technorati, with “384,996 weblogs watched,” that recently launched a new Keyword Search (Beta) feature that supports Boolean searching.