Source: http://feeds.gawker.com/~r/lifehacker/full/~3/c8ApdLREi_c/yacktrack-keeps-an-eye-on-comments
YackTrack is a comment tracking service. If you've ever wondered who is talking about a blog post or news article you can enter the URL and see who is talking about it and where.
YackTrack currently tracks comments on Blogger/Blogspot, Digg, Disqus, FriendFeed, Google Blog Search, Google Reader, IntenseDebate, Mixx, Reddit, StumbleUpon, Technorati, TypePad/MoveableType and WordPress blogs. Additionally there is a "Chatter" function that lets you search for key words instead of single URLs. On the time saving side of things it's possible to set up a bookmarklet to help you search YackTrack and you can turn a search term into an RSS feed to plug it into your favorite reader and stay abreast of new comments.