If you select Direct Connect search type it should show what your ip address is. If not then you're probably both firewalled which would make it extremely difficult to DC. See: How to Direct Connect, Browse & Chat

For ip see: http://www.whatismyip.com/

Hope you both configured your firewalls, etc. to allow LW access: http://www.limewire.com/english/content/firewalls.shtml