Security problem with php

Hi all.
I have a domain hosted with a provider with php3, mysql, apache, ...
The question is that I have read that if I want to have password or
important files,
I need to run the php3 scripts with my user id instead of the default
nobody.
Is this the correct way?
If my host provider don't let me use a cgi-wrapper or the Apache suEXEC
module
are not enabled, How could I resolv the problem?

I like to know what's the best way fo with  security management with
php.

Thank you.

Antonio.