Over at Pharyngula people often ask how to install killfile, which selectively hides comments in blogs.
First, it's assumed that you're running Firefox. AFAIK, there is no analogous functionality for other browsers (please comment below if you know otherwise).
- Install the Greasemonkey user script extension.
- Restart Firefox
- Install the killfile script by clicking on the large black Install this script button at the top of the page.
Now, when you load a page on ScienceBlogs (and any of several other blogs) each post will have two new bits of hot text in the Posted by: line: [kill], which hides all comments by this poster in every thread; and [hide comment], which hides only the single comment.
In place of a hidden comment, a one-line notice appears saying “Comment by User Foo blocked [unkill] [show comment]”. Clicking on [unkill] reveals all of the posts by that user; clicking on [show comment] reveals just the single comment.