SFDonovan you may want to give this a try:
I modified the approach based on the discussion on this apple support page: http://discussions.apple.com/thread.jspa?threadID=2174107&tstart=0
1. Download php-5.3 from http://us2.php.net/downloads.php
sudo the following
2. cp pcre.h from php-5.3/ext/pcre/pcrelib to /usr/php/ext/pcre
3. pecl install zip
It says it completes and all one needs to do is add exactly what you suggested to the php.ini. extension=zip.so
It took me a bit to figure out the php.ini setup too. So in case you have not. In /etc/hosts there is php.ini.default. It says to copy that to php.ini and modify that. I also read in a wordpress support page that all those timezone warning can be eliminated
if you set the date.timezone line to something meaningful. The example I saw was Europe/Dublin and America/Chicago so I have tried America/Denver. This default ini file does not display errors so you may want to toggle that too.
I haven't had a chance to see if any of this works and may not today so I thought I would post what I have done so far in hopes that it may be useful.