Bryan's Tips and Tricks
Enable the Basic PHP Server in Leopard (Mac OS X 10.5.2 Leopard)
We have already gone over how to enable the Web (Apache) Server in OS X. But lets say that you want to do some more advanced stuff than just basic HTML and CSS. Once you've graduated to PHP, you'll also want to enable the PHP Server so that you can render and run your PHP locally.
Enabling PHP isn't nearly as simple as Enabling the Apache Web Server, but if you follow the steps below, you should be writing PHP before you know it. :)
So Here's How:
Open Terminal (Located in your Applications Folder under Utilities.)
Type in cd /etc/apache2 then press enter.
Next type in sudo pico httpd.conf then press enter.
It will ask you for your password.....type it in and press enter.
Note: You need to actually have a password set. Using a blank password did NOT work for me.
You can do this in System Preferences --> Accounts.
This will launch a really ugly, unfamiliar text editor. Don't Panic.
Press Control-W (search), type in php and press enter.
Now, delete the # from the #LoadModule php5_module line leaving only LoadModule php5_module.
Now press Control-X, then type y and press Enter (to save changes).

Screen of Terminal displaying "Pico"
You can now Quit from Terminal like you would any other application.
You now need to restart the Web Server. If you know how to do this without rebooting, have at it. If not, just restart your computer.
That's it! Your machine should now be able to render PHP code using the Local Web Server.
Here is an explanation of the commands we used today:
cd : Changes the directory to whatever you specify.
Note: To change to a directory that has a space in it, you have to put the directory in single quotes: example: cd 'My Music Folder'
sudo : Makes you a Super User for a given command. Allows you to modify things that belong to someone else or to the system.
pico : This starts the Unix Based Text Editor "Pico".