gistfile1.rb

require 'nokogiri'
require 'open-uri'

doc = Nokogiri::XML(open('http://search.twitter.com/search.atom?q=%22Black+Friday%22'))
doc.xpath('//ns:title', { 'ns' => 'http://www.w3.org/2005/Atom' }).each do |title|
  puts title
end

__END__
####
# Why namespaces are important
#
# Take this XML for example:
<root>
 <car xmlns:part="http://general-motors.com/">
  <part:tire>Michelin Model XGV</part:tire>
 </car>
 <bicycle xmlns:part="http://schwinn.com/">
  <part:tire>I'm a bicycle tire!</part:tire>
 </bicycle>
</root>

###
# Say you were to search that document for a 'part:tire'.  You would
# get back 2 nodes.  Unfortunately you were not using proper namespaces,
# which means you cannot tell the difference between a bicycle tire and
# a car tire.