In ubuntu we need to change the /etc/apache2/ports.conf file.
sudo vim /etc/apache2/ports.conf
Change the port to listen on something other than 80.
/etc/apache2/port.conf should now look similar to this.
#file: /etc/apache2/port.conf Listen 8080 Listen 443
Edit VirutalHost Files
Update your virutal host files to use port 8080 as well.
<virtualhost> #..... </virtualhost>
sudo service apache2 restart