without_timestamps.rb

require 'proxy_block'
module WithoutTimestamps

  def self.included(base)
    base.send :extend, ClassMethods
    base.send :include, InstanceMethods
    class << base; proxy_block :without_timestamps; end
    base.send :proxy_block, :without_timestamps
  end

  module ClassMethods
    def without_timestamps
      original = self.record_timestamps
      self.record_timestamps = false
      yield
    ensure
      self.record_timestamps = original
    end
  end

  module InstanceMethods
    def without_timestamps(&block)
      self.class.without_timestamps(&block)
    end
  end

end