Thanks for the tips guys. Netstat reports that httpd is listening to port 80. It seems the problem was iptables as stoping the service as advised allowed me to reach the Apache test page successfully.
Two problems however:
1) I tried adding this rule to accept incoming connections on port 80 with iptables turned on, but it doesn't seem to be working:
iptables -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
2) I've configured name based virtual hosts in Apache but these aren't working and I'm only getting the test page. This is a separate problem so I'll repost.
Any ideas about the iptables rule? Thanks for the help.