Shoutbox

You need to get their IP address...best method is;
Send a file type netstat - n into command prompt in transfer then you'll get a list of addresses...one will be the contact...
then use a trace program to find their approximate location (tracert in command prompt will do this) or McAfee Personal Firewall Plus will give you a graphical location...
Without being the FBI, CIA or NSA that's the best you'll be able to do...