FWIW, I put Nagios in /home/nagios/html, and use an apache VirtualHost directive in a conf file in /etc/httpd/conf.d
Interesting. I don't know much about these virtual hosts, and will look more into it.
I assume this is where I need to look?
http://httpd.apache.org/docs/2.0/vhosts/
and
http://www.devshed.com/c/a/Apache/Configuring-and-Using-Virtual-Hosts-in-Apa...
thx, John!