OS X FIREWALL:
To open the OS X Firewall for Gnutella access, please do the following:
1 Open up 'System Preferences'
2 In 'Internet & Network', open 'Sharing'.
3 Select the 'Firewall' tab (your Firewall should be on)
4 Select 'New...'
5 From the 'Port Name' drop down box, select 'Gnutella/LimeWire'
6 Select 'OK'
7 Restart your LimeWire application.
I followed this up to number 5, but the drop down box only lists CVS, ICQ, IRC, MSN, Quicktime, Retrospect, SMB (without netbios), Timbuktu, VNC, WBEM, Webstar Admin and Xcode distributed build.
Where is Gnutella?