The netstat thing, I assume you are talking about when they direct connect to your computer, and you type in netstat (no commandline operators) and then look for port 4443. That should be there ip address. If that doesn't work than I don't know what will. Try google, "aim ip address sniffer" that will bring up some interesting hits.
"Computers are one per cent inspiration and ninety-nine per cent perspiration. Accordingly, a 'computer' is often merely a talented machine who has done all of its homework."
-Thomas Edison, Modern Day.