You can run fshostclient for fsx on a second PC successfully. I'm posting this because as most of us know (or don't know), on lower end PCs like mine with a dual core processor I have to run FSX in full screen mode. By doing this, it is a pain to alt-tab all the time just to chat and enjoy the sim at the same time.
There is a thread here on how to set it up.
http://www.chocolatesoftware.com/forum/ ... opic=711.0FYI: You can also use Flight Sim Commander to view multiplayer traffic worldwide. See the other sticky in this forum.