The Google Blog Search results have generally been the fastest and most useful tool of this kind (Google displaced Technorati, which had long served in this role, some time ago). But a couple of months ago Google Blog Search started becoming pretty much useless. Instead of only reporting links from the “main” blog content, it reported all links on a blog page, including the so-called “sidebar” or blogroll, where many bloggers place a lengthy static list of blogs they read. So this means that, for instance, every time JD Lasica adds a new post to his blog at Social Media, which includes Wordyard in its blogroll, I get a new listing in the Google Blog Search for Wordyard, even though the post has nothing to do with Wordyard.
I noticed this immediately. Google Blog Search went from being incredibly useful to utterly useless for me. Google Blog Search results for links to daringfireball.net now include every single update from any site that links to the Markdown Syntax documentation, for example.