cd /usr/ports/databases/phpmyadmin/
make install
...

Using existing group `www'.

phpMyAdmin-3.4.7.1 has been installed into:

    /usr/local/www/phpMyAdmin

Please edit config.inc.php to suit your needs.

To make phpMyAdmin available through your web site, I suggest
that you add something like the following to httpd.conf:

    Alias /phpmyadmin/ "/usr/local/www/phpMyAdmin/"

    <Directory "/usr/local/www/phpMyAdmin/">
        Options none
        AllowOverride Limit

        Order Deny,Allow
        Deny from all
        Allow from 127.0.0.1 .example.com
    </Directory>

===> Correct pkg-plist sequence to create group(s) and user(s)
===>   Registering installation for phpMyAdmin-3.4.7.1

в /usr/local/etc/apache22/httpd.conf добавляем

Alias /phpmyadmin/ "/usr/local/www/phpMyAdmin/"

перезагружаемс веб сервер
/usr/local/etc/rc.d/apache22 restart