coolman: Port 81 won't work just because a school's computers are set up to browse the web. Browsing the web doesn't require any external connections. Your browser initiates the connection and it's the server you are connecting to that has to have port 80 or 81 open. You are confusing inbound and outbound connections. In other words you need port 80 (or 81) open to run a web server, not a web browser.

I used to advise people about this very issue during the STG era and the results were always the same: either they couldn't circumvent the firewall, or they never reported back to us on the results, which probably amounts to the same thing.

I can't see why a school with even a half-decent firewall would leave any of these ports open. It's worth a shot, but based on the results I've seen, you most likely will just have to live with being firewalled, or you will have to specifically ask your admin to open a port for you. Good luck.