I decided to upgrade to PHP 5 because it was required by an interesting tool called activecollab.
PHP 5 nicely shuts off Register_Globals so that all your global vars go away... magically. Well just about everything I've written uses global vars. Nice. Gotta edit /etc/php.ini to turn it on again.
One more thing... $id no longer works. Must be taken over by something else in PHP 5.
http://www.php.net/downloads.php#v5