As recommended by Google Preferred Site Search (now in Labs). These were probably gleaned from my search history, and yup, they look about right.

api.rubyonrails.org

code.google.com

giantrobots.thoughtbot.com

github.com

groups.google.com

linuxforums.org

linuxquestions.org

macosxhints.com

mythtv.org

railscasts.com

ruby-doc.org

ubuntuforums.org