in httpd.conf look for the line "Listen", which then you could do:
Listen *:8080
to listen on all connections on port 8080, or specify a specific connection based on IP:
Listen 192.168.1.2:8080
NOTE: You can also define per-IP stuff in the <virtualHost> config.:
<VirtualHost 192.168.1.3:8080>
ServerName mydomain.com
DocumentRoot /home/httpd/vhosts/mydomain.com/httpdocs
</VirtualHost>
<VirtualHost 192.168.1.2:8081>
ServerName alt.mydomain.com
DocumentRoot /home/httpd/vhosts/mydomain.com/httpdocs
</VirtualHost>
In this way you can use multiple IPs to create "alternate" ways to get to your site. Or if you want to host part of your site on a specific IP for whatever reason. You can also change the ports there as needed.