I was going to do a somewhat long and drawn out method of obtaining a port match to process ID and how to find out what program is using that process ID(to help people running game servers and chat programs etc.), however it looks like Microsoft finally updated one of their network/system diagnostic tools. For those of you who use netstat already will find the new features to be long awaited, and for those that have not yet used it may consider using it for helping you diagnose network/firewall issues potentially brought on with installation of Windows XP SP2.

netstat -b

... snip output ...

 TCP    CORVETTE:2155           216.179.194.253:8000   ESTABLISHED     3452
  [wmplayer.exe]

  TCP    CORVETTE:2195           akonix1.mycompany.com:5050  ESTABLISHED     2152
  [trillian.exe]

From this you can see that my company setup a proxy for most instant messengers.