Use port routing (triggering) on your router if you have one to route an unblocked port (commonly 8080) to an internal port 80. If your router doesn't have this feature you can change the listening port on whatever webserver you use to the unblocked port. You can then either append :xxxx where xxxx is the port # you choose to your url or get a hostname that can forward to your appended url.
As always if you are serious about your server you can always get a web hosting service for your site. Their ISPs never block port 80