Returning External IP Address = "Error: Blank Use"

I've noticed that the game now returns a string "Error: Blank Use" where the external IP address should be in multiplayer. This is because the site the game used to use for finding it went down. So if you see "Error: Blank Use" where the external IP should be, then you'll have to find your external IP yourself by visiting one of these sites:

http://whatismyip.org/
http://whatismyip.com/