When newbies show up asking why their global vars don't work on PHP 4.2.0+ - please don't tell them to turn register_globals on. They should be encouraged to use $GET, $POST, $_COOKIE etc, not just given the cheap, quick fix.
register_globals is off in 4.2.0+ because there are security issues surrounding variables registered in global scope - not just to make life difficult for people.
Thanks
Mike