Learning by example

Hi,
I want to get into rails. i learn the best by seeing a built app and
watching how it was written.
where can i find typical open source rails project that i can download
and learn from ?
i'm interested in facebook connect integration tag clouds, searching in
my website

Thanks!

http://railscasts.com
http://teachmetocode.com
http://railstutorial.org

-sunny
http://ezror.com