Today Ritu Kamthan created a search engine for RubyOnRails (powered by Google Co-op)

Presently it searches over following sites:

weblog.rubyonrails.org
wiki.rubyonrails.com
rituonrails.wordpress.com
webonrails.wordpress.com
fromdelhi.com
vinsol.com
rubyonrails.org
ajaxonrails.wordpress.com
del.icio.us/
www.rubycentral.org
www.rubycentral.com
www.ruby-lang.org
www.rubyonrails.com
nubyonrails.com
rubyforge.org
sitekreator.com/satishtalim/index.html
dec.orat.in/
den1jay.blogs.assembla.com/

If you are a regular rails blogger and wanna add your site to this list, please let me or Ritu know, so that we can include your site.