open_basedir without safe mode?

Hi there, I was wondering if there is a possibility to get open_basedir preferences (also set via .htaccess) active in a server running not PHP in open_basedir. I should create a small home site space for some users with PHP equipped, but I don't like to put safe mode on as there are some other advanced (not runnable in safe mode) scripts on the same machine. open_basedir would limit the user's access to their own directories, but it seems not to work wihtout safe mode. Any ideas? Ville