Net::HTTP.get_print 'www.gun.io', '/'
That's it! In only two lines of ruby, you can grab a whole webpage and print it to the screen. Awesome! - and it's in the standard lib ;)
I agree, when I left PHPland I chose Ruby over Python because the (web) community was larger, there were just more books, blogs, screencasts, etc for Ruby/Rails.
There seems to be more ideas generated out of the Ruby community, I'd add Sinatra and HAML to the list above, like Rails they've both been ported to other languages.
OF course Heroku was Ruby first and it's so good that my PHP/Java/Python friends jumped for joy when their language became supported.