aggregator.rb

aggregate(:twitter, "http://search.twitter.com/search.atom?q=from:gacha") do |doc|
  (doc/:entry).collect do |item|
    {
      :created_at => (item/:published).inner_html,
      :value => (item/:content).inner_html
    }
  end
end

aggregtor.yaml

- :object:
    :name: twitter
    :feed:
      :url: http://search.twitter.com/search.atom?q=from:gacha
    :find:
      :conditions:
        :xpath: //status
      :limit: 5
    :created_at attr: :created_at
  :attributes:
  - :name: :created_at
    :find:
      :conditions:
        :xpath: /created_at
        :datetime: true
  - :name: :text
    :find:
      :conditions:
        :xpath: /text