So with the security patch 2008-005 for OS X 10.5.4, Apple finally brings their built-in PHP to 5.2.6. Unfortunately for me, this means that installing the security patch overwrote the custom built version, I'd installed as an interim patch. So I had to go back today to phpize a bunch of extensions and install them. pgsql, gettext, and gd being three big ones.
Just discovering that it seems to have overwritten my PEAR history and config as well. Oh well. Everything can be rebuilt.