installing Geocoding pear libraries for php

first navigate to your current php install directory mine is currently in mamp:
cd /Applications/MAMP/bin/php5.3/lib/php/

in that folder run the following commands:
sudo php -f pearcmd.php channel-update pear.php.net

then run:
sudo php -f pearcmd.php install channel://pear.php.net/Net_GeoIP-1.0.0RC3