Now how to look at this can be confusing unless you know what your looking for. If you have a instant message program such as "aim" and you direct connect to someone you have a "established connection" with them. So using this cmd command you can view their ip.
Usually the port number is "4443" and i noticed sometimes it doesn't work so i am guessing it is because that the person has a firewall. So here is the script.
open notepad and enter the following:
@echo.
@color 09
@netstat -n
@echo.
@pause
then save as "GetIp.cmd" and when opened you will view all established connections.