Here's a suggestion for a NAT checking utility developed by displaced for Acquisition. LW should have such a utility too, because it checks to see if a user is properly configured to connect to gnutella.
I don't if this bookmark of mine will work here for others:
http://www.sciforums.com/f72/s/showt...threadid=20514

If not, maybe someone who understands Applescript could look at this: http://homepage.ntlworld.com/chris.p...ecknat.app.sit