def add_message(msg, tags={})
      unless msg.kind_of?(Selectable::Object)
        msg = TaggableString.new msg.to_s
      end
      msg.add_tags self.default_tags
      msg.add_tags tags
      @messages << msg
      msg
    end
def add_message(msg, tags={})
      unless msg.kind_of?(Selectable::Object)
        msg = TaggableString.new msg.to_s
      end
      msg.add_tags self.default_tags
      msg.add_tags tags
      @messages << msg
      msg
    end
+msg+ is the message to store. This can be any type of
 object that includes Selectable::Object (so that tags
 can be added to the message to retreive it later). If
 +msg+ does not include Selectable::Object it will be
 converted to a TaggableString object.