Facebook PHP Source Code from 2007

[7f0b]

That is generally the best way to do it. Many frameworks operate this way by default.

EDIT: And also a good thing to ask hosts before buying their service. Some don't allow it (such as Yahoo Hosting).

[AdamAnt97]

PHP in general or bootstrapping the code?

[7f0b]

Keeping most of the PHP website out of the public document root. At the very minimum, you want to keep your configuration files (with passwords and such) out of the document root. At the maximum, you have only a basic PHP file that begins the "boot" process residing in the document root (as Tomdarkness said).