Then the 3G ISP blocks port 80. I use port forwarding for this stuff.
In the Arduino code, you should change the port from 80 to 8085.
In the router, you should forward (destination nat) port 8085 to your localnet ip for the Arduino. Can you find that in your router setup stuff?
edit: Then from your friend's computer:
http://197.110.30.232:8085