On PHPClasses.org there's a tutorial posted from Michael Fuhrman about getting a LAMP environment set up with Samba. This setup will allow a single server to serve up sites stored on remote machines and accessed over a Samba share.

Web sites can be served using PHP scripts stored in a different machine than the actual Web server machine. Read this article to learn how to setup a Fedora based Web server machine (without a desktop GUI) using Linux, Apache, MySQL, PHP and using Samba to serve sites using files shared by separate machines.

He steps you through the installation of everything you'll need - a VM to set up the server on in VirtualBox, configure the network interface and the packages/configuration updates you'll need to make. It's a pretty lengthy tutorial as it includes every single step you need (and sometimes its output). One note on this method - because it would be accessing the files over the network for each Apache request (possibly multiple) it will cause much more latency than if they were on the local machine.