Got it and verified it: I can be seen from the outside. Loopbacks were the problem.

So it turned out that my server didn't support loopback and that once I worked out port forwarding I was on the web but that I couldn't see myself from inside the network.

I verified this by using a proxy server:

http://anonymouse.org/anonwww.html

which was sent to the external address given by Google to the query "what is my IP address".

I tried again with the web address that I had forwarded to the computer using an A record and it worked again where it hadn't worked before.  I'm live!

Trendnet router reset: This makes me feel safer

http://portforward.com/networking/forgot-router-password.htm

Basically, if you ever were to lose the username and password associated with your router, you can put it back to factory settings using the reset pinhole.  On my Trendnet that pinhole is on the front right below the power jack.

For most TrendNet routers, the reset leads to
username=admin
password=admin

See the portforward link up top for more details if this doesn't work.

Getting the internal IP of your router

ifconfig is good for finding your internal IP number and other information, but to set up port forwarding you need to find your router internal IP number.

If you see an IP number that is referred to as "default gateway" or just "gateway," that's your router's IP number.

If you're connected by ethernet, you can find that number using the following command:

$ nmcli dev list iface eth0 | grep IP4

See askUbuntu.

Okay, I just found a better way for out-of-the-box ubuntu on sudo juice:
$ nm-tool

This will give you your router IP, which it calls "Gateway."