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+##########################
+Creating Ancillary Classes
+##########################
+
+In some cases you may want to develop classes that exist apart from your
+controllers but have the ability to utilize all of CodeIgniter's
+resources. This is easily possible as you'll see.
+
+get_instance()
+===============
+
+**Any class that you instantiate within your controller functions can
+access CodeIgniter's native resources** simply by using the
+get_instance() function. This function returns the main CodeIgniter
+object.
+
+Normally, to call any of the available CodeIgniter functions requires
+you to use the $this construct::
+
+	$this->load->helper('url');
+	$this->load->library('session');
+	$this->config->item('base_url');
+	// etc.
+
+$this, however, only works within your controllers, your models, or your
+views. If you would like to use CodeIgniter's classes from within your
+own custom classes you can do so as follows:
+
+First, assign the CodeIgniter object to a variable::
+
+	$CI =& get_instance();
+
+Once you've assigned the object to a variable, you'll use that variable
+*instead* of $this::
+
+	$CI =& get_instance();
+
+	$CI->load->helper('url');
+	$CI->load->library('session');
+	$CI->config->item('base_url');
+	// etc.
+
+.. note:: You'll notice that the above get_instance() function is being
+	passed by reference::
+
+		$CI =& get_instance();
+	
+	This is very important. Assigning by reference allows you to use the
+	original CodeIgniter object rather than creating a copy of it.