<p>Using Ruby and Thin as a web service.  Apache is also loaded.  Can't access the web service because listing ports, such as <code>:3000</code> or <code>:6600</code>, in the GET url is not allowed.  How is the port requirement removed?</p>

Use Apache ProxyPass.
cd /etc/apache2/sites-enabled/
sudo vi 000-default
Edit Lines:

    ServerAdmin webmaster@localhost
    ProxyPass /breakfast
http://localhost:4567/breakfast
DocumentRoot /var/www
sudo /etc/init.d/apache2 restart