Why can't I access my server (running XAMPP on Ubuntu) remotely?

Why can't I access my server (running XAMPP on Ubuntu) remotely?

I've been developing locally on a little Ubuntu netbook with XAMPP for about 7 months. Two weeks ago, I got a computer I'd like to use as a server. I've installed the latest Ubuntu distribution and XAMPP, moved all my files over, and forwarded port 80. I've also got a domain name from dyndns.com which is being updated by a client which runs in my router (a Netgear WGR6154 v8).