How to load/enable/install GD library in os x

[coldwerturkey]

I'm trying to get a thumbnail creation script that works fine on my remote server to work on my local server (late '07 macbook)

but with the check

    if (!extension_loaded('gd') && !extension_loaded('gd2')) 
    {
        trigger_error("GD is not loaded", E_USER_WARNING);
        return false;
    }

i get the error

Warning: GD is not loaded in /Users/.../thumbnail.php on line 9

I searched and read to enable the gd library I had to go into php.ini and remove the semi colon from the following line,

;extension=php_gd2.dll

Which I did, and restarted apache, but am still getting the error.

So my question to you is how do I install the gd library? Or does anyone know if it comes preinstalled on os x and how to enable it?

(I don't know a lot about this... sorry if I used the wrong terminology.)