Show Local LAN ip address?

Anyone know of a way to get Max to get the local ip address for the computer (not the internet one). Just thinking for a network app where there's a host and remote app (UDP/TCP) and for the remote app to talk to the host one the user would somehow have to enter ip and port or the other computer right? (To set up the link)

Just wondered if a patch could helpfully display it so the user doesn't have to go into OS to do it. Also it should be cross platform?!? Any ideas?

Thanks.