Christopher Jones has a new blog post today that gives the steps for upgrading your PHP installation on an Oracle Application server running on Linux.
Oracle includes PHP with its mid-tier Application Server 10g Release 3 allowing you to use the same web server for PHP and for J2EE applications.
He starts with where the files are located (configuration and executable) and the steps to follow to get things updated, compiled, and in working order. Their version of choice is PHP 5.2.2 (though PHP 5.2.3 was just released to help correct some other security issues found).