gistfile1.rb

class Article < ActiveRecord::Base
  after_create :submit_to_crossref

  private

  def submit_to_crossref
    CrossrefRequest.new(:title => title,
                        # other info for the request
                        :author => author).submit
  end
end

class CrossrefRequest
  def initialize(attributes)
    # set attributes
  end

  def submit
    # call helpers to format and submit the request
  end

  private

  # helper methods related to formatting/submission
end