<?php
class DataContainer
{
	private static $data = array();
	
	public static function __set( $name, $value ){
		if( ! isset( self::$data[$name] ) )
			self::$data[$name] = $value;
		else
			return FALSE;
			
		return TRUE;
	}
	
	public static function __get( $name ){
		if( isset( self::$data[$name] ) )
			return self::$data[$name];
		else
			return NULL;
	}
}

$dc = new DataContainer;
$dc->FILE = basename( __FILE__ );

var_dump( $dc->FILE );

$dc_two = new DataContainer;
$dc_two->FILE = 'mettigel';

var_dump( $dc->FILE );