Google Blogsearch
Google helps you search web sites, it helps you search newsgroups, it helps you search your computer... now it helps you search Blogs.
http://blogsearch.google.com/blogsearch
It seems to be truly dynamic... with search results changing regularly depending on who is the very latest to mention a particular topic. For a short while there, I was the number one hit for 'Patchou' and I'm still number one hit for 'Trend Antispyware' - thanks to this entry:
http://msmvps.com/spywaresucks/archive/2005/07/16/57639.aspx