Atheist Blogroll Search Plugin is now available for Firefox.
File-> Atheist Blogroll Search Plugin.xml
For Windows right-click and save this file in:
C:\Program Files\Mozilla Firefox\searchplugins\
You may need to restart Firefox.
Have fun searching all 500+ Atheist Blogroll blogs.
Note: This plugin is not yet available at Mozilla. Still working on the file structure. This particular version was accomplished with OpenSearchFox :: Firefox Add-ons (no longer available) whereas after adding the search plugin I went and sequestered the .xml file from my Firefox directory.